With the proper disguise a person can openly walk into most low to medium security buildings. The most important trick to daylight infiltration is to look like you know where you're going. People are less likely to stop someone if they look busy or in a hurry. A second trick is to look as if you belong. It sounds easy but it can be harder than it looks. For example, everyone is comfortable with the UPS man, so coming in with a dolly full of boxes is to be expected if you have the uniform. A soft drink stocker is expected to have a dolly full of pop cans. Nobody needs to know that they are empty and are only at the surface.
Perhaps the easiest disguise for a larger building is a pizza delivery man. After a little persistent search on eBay, a hat and polo shirt/t-shirt with a big pizza company's logo on it can be picked up second-hand for about $15. Whatever car you have should have a pizza "light" mounted on the top...which is basically a magnetically-attached light that plugs into your cancerette lighter socket. You can simply get one of these by ordering a pizza, and when the delivery guy comes with the pizza, have a fellow brother/sister swipe the light while the transaction takes place.
Quite often you can get through a building without second-glance by simply dressing up a bit. Very few people will ask questions to a man with a decent-looking business suit on. After all, would you want to be the piss ant worker http://wiki.stealthiswiki.org/wiki/Infiltrating 1/6 who asks the VP of Ass-kissing for your company what he's doing there?
If a building requires an ID inspection to get into a building, this is not very difficult to replicate usually. Try to get a good look at the badges by the people entering the building. Notice the actual ID and its features, then notice what most wear their ID's on (attached to a cord, on a clip, etc.). The most important thing, however, is to see how carefully the security guard inspects them. If he barely looks up from his episode of Jerry Springer to wave you in, simply flashing a baseball card at him may suffice. If he carefully inspects it for a brief moment, he's checking something specific (usually picture or expiration date).
An important tool for a revolutionary fighter is a nice set or two of business clothing. By wearing the ceremonial costume of CorpGov you will become almost invisible to many police, security, and other enforcement bodies who are expecting to see pierced, dreadlocked punks. Wearing clothing of this type will allow you entry into most offices and banks unhindered. With some planning you can claim to have business with a manager, sometimes the security desk will even have access to the building directory and help you find the office you want. Once you arrive if protest is what you like do a Clark Kent and rip off those ties and coats to reveal t-shirts with your slogan. If you tell a no-brand thrift store you need to make a job interview they might give you a discount on this type of clothing, but often a department store with an old guy as a salesman is a better choice for your monkey suit as sloppiness in dress and hair is a giveaway that you really don't fit in the starched CorpGov environment.
Although the best method is to observe actual employees of the targeted company, here's a good rule to go by: in 21st century United States most higher-ups will be seen wearing a quality matched wool suit coat and trousers, white shirt, conservative tie, dress black shoes and well trimmed hair. Female Manager types will also be seen in a wool tailored skirt and matching jacket, makeup, medium heels or flats, and styled hair. Even in high tech where lax dress is the rule, tech managers might get away with more casual, but the creepy biz-school types still go for the suit. Creepy means nobody bothers you.
For impersonating your average wage slave, wear a quality set of trousers, belt, dress shoes, and nice, button-down, tucked-in (VERY IMPORTANT) dress shirt, and tie. Many men these days have their hair cut short to reduce "antihippie" profiling, hair drug test anxiety, and time and money to care for.
1) Cell Phone
Most people have a cell phone close at hand. One way to fake the cell phone is to get a holder/case and a plastic dummy. With the right holder, no one will be able to tell the difference. For men, attach this on your belt. For women, the cell phone is less important as many women carry it in their purse or pocket (out of sight). Thus, the charade is unneeded.
What is special about the cell phone is it creates an impenetrable "don't bother me" bubble and social norms cause most people to respect this. Use this magic "don't bother me" effect to your advantage.
Briefcases are an expected accessory for medium level executive types. Often there is now a cursory search of briefcases and purses when entering office buildings. If you can slip your secret stuff into the walls, false bottom, or folders inside you are likely to get in with no problems unless there is an x-ray scanner which is very rare. The more important the exec the smaller the briefcase is, but assistants may have a huge support load to carry for their boss.
To look like you you belong, you must feel like you belong. Copy the busy slave brisk walk, watch how the monkeys walk and move, a few days of study will be valuable. If you give off a sense of authority, suspicious people will often stay away to prevent being questioned by the bigwig from corporate. It can be useful to have a well dressed accomplice who you give orders to, like a mobile secretary or assistant-type taking notes and such.
Posture is as important as clothing. Suck your stomach in, roll back your shoulders, and do NOT stick out your chest. Make sure to hold your head high. Do not deviate from this. Slouching afterwards will cause your shirt to wrinkle.
It is just fine to ask questions of employees how a system or program works. Ask them to demonstrate; most users will even turn over their login password so they can show you a login. Remember: you are a corporate bigwig; why shouldn't they let the VP of auditing see all of this inside information? Let a kissup who wants a promotion lead you around or show you the vital areas. He can be your cover.
Confidence, coolness, and a bit of arrogance will get you a long way. Keep moving and everyone will think you are passing through and you know where you are going. If you pause as if lost or make a worried eye contact, the questions and suspicions will begin. Look on the directory outside and know a few manager names to drop as a last ditch dodge if people start asking questions. You will likely get one shot at infiltration, so make it count. People might talk around the water cooler and might figure out there is no VP of Auditing after your visit. There is little chance of an employee admitting that he was the dolt who gave you a login or password, so even if there is a security audit later on, all may not be lost.
Due to continuing enforcement of 1970's-era "30 day" password rules and rules requiring random letters and numbers in a password at many companies, you can usually get most of the login information you need from a note in the desk drawer, cubicle wall, or a post-it note stuck to every monitor.
If you are setting up a snoop, secret server, or other device, waltz right in and set it up -- unless it is very suspicious you should have no problem. A regular empty tower computer case is a great toolbox, you can sneak all kinds of things in hidden inside.
Remember, the low-paid janitors, handymen, cafeteria workers, etc. are looked down on and paid little (usually minimum wage), while the bosses earn thousands, perhaps millions. They will probably help you out for a small price or as a way to "get back" at their employers.
Keep your eyes open for higher-ups that are overly nasty to their employees. Many employees with unnecessarily mean supervisors would gladly look the other way if you wanted to sneak into an office to look at files, get keys, etc.
If you troll the pubs near the business you can often lift a pass key/card from an employee. Sadly, many office workers are very lonely. Thus, some attention from an interested party can often get amazing results that years of hacking would fail at. "Accidentally" meet up with your mark if they like to frequent a bar and lift what you need once they are full of liquor.
You will need good information on the security in the place you wish to infiltrate. Know where cameras and sensors are located, and how sensitive they are, play with the sensors and see what lights the indicators during a daytime visit if possible. An insider might know if the security system is tied into door locks and if there are any alternate escapes. If you do screw up and set off the alarm then go to S.E.R.E. mode.
The crude way to disable a camera is to zap it with a few paintballs or spraypaint, this makes it clear that tampering has happened when the donut boys make their rounds. With the availability of cheap lasers a more sophisticated attack can be made. Tape the switch down on the laser and aim into the camera lenses as you are coming around the corner, use a dental mirror to help you see around, this will almost always wash out any image on the camera, since you have work to do laser-dazzle the hands free way, stick the laser high up on the wall with modeling clay(remember clay takes fingerprint impressions). All that this will do is wash out the image on the camera, if you aim is good and the guard is stupid he might not notice the laser is shining into the camera when he checks things out. If you tie string through the clay you can yank your laser around a corner after you get past.
Making a laser dazzler from a green laser pointer or scavenged blue-ray DVD burner laser module or even a regular DVD burner has a better chance of blotting out the whole camera image and possibly even burning out a camera without any obvious outside damage. It might do to wear laser goggles or at least use wrap around sunglasses with laser resistant film taped inside (get at a science supply store or university physics lab, know the frequency of the laser you are using) since these are powerful lasers.
Motion and Infrared Sensors
Motion sensors emit a sound or microwave emission and if there is a Doppler change in the returned microwaves or sound the sensor will alert, many sensors will blink a light if this happens and not trip the alarm right away. If you move very slowly you should be able to get past the motion sensor. Some motion sensors if blocked with a piece of wood(sound) or aluminum foil(microwave) they will alarm. Most sensors have an advertised sensitivity cone of 90 degrees. Believe it or not, holding a sheet between you and the sensor, while walking slowly can do wonders.
Infrared sensors detect a sudden change in the ambient infrared signature of the room, if you can slowly reveal yourself or cover your infrared with a piece of furniture so that the little detect light is not indicating you have probably made it in. Covering the alarm may set off an alarm since this will cause a sudden change in detected infrared energy. Better to put a desk or couch in between your movement path and the sensor.
If you can simply disable the alarm connection line (some dial on a normal phone line some have a dedicated alarm line) this might be the best option, be sure to put a resistive load back onto the line (have a multimeter and selection of resistors handy), a cut alarm line will always indicate a fault and security or police will usually be called. Once the line has been disabled you will likely still have to contend with loud sirens on site if you trip the system. Be wary a few alarms use a wireless transmission to the security booth or alarm company. Do not assume a power outage will knock out the alarm, most have batteries.
Your best escape is knowing where to run. Once trapped, you might be forced to fight, making your legal situation much worse should you be arrested. For more good escape info see S.E.R.E.
Remember, no matter how perfect and planned your operation is, there will always be several factors to give you away, which you must be prepared for in advance. If possible, find as many plans of the building you are to infiltrate in advance, and study them - make sure these plans are as up-to-date as possible. Mark all entrances and exits, rooms you will be targeting, and possible areas of importance to both yourself and staff. You will need to memorize the entire building layout - failing this, at least make sure you can remember the way to at least three escape routes at all times. Don't forget to look into underground escapes which are sometimes overlooked at first by the cops, electrical, telephone, and sewer access tunnels might be the best way out, an insider or public records may help you find this information.
If the situation warrants it take a concealable weapon along with you. Seriously consider the cost/benefit ratio of when choosing to bring a weapon it could move a misdemeanor breaking and entering charge to a serious assault or weapons felony even with less than lethal devices.
A great device for emergency exits is the small fire extinguisher turned pepper spray blaster in Weapons for Street Fighting, it should clear out a floor or two even in a large building. Of course, you will need a gas mask or respirator and goggles in your bag to use it effectively.
Briefcases should really be used on every infiltration, because the uses of the items stored inside outweigh the risks. Wait outside the building you are targeting when staff are leaving - check out the size and shape of the briefcases they are using, so you will be able to blend in even more. Now, here comes the most interesting part - packing your briefcase. Keep it light, but don't leave out any of the essentials. Take a plan of the building, a balaclava (don't try any other method of covering your face, as masks, helmets etc. are impossible to conceal in a briefcase), and a paintball marker and around fifty paintballs - these can be used to temporarily "blind" CCTV cameras, but you will need to practice well to hit your target, don't forget how loud a paint marker gun is. After these items, the contents of your briefcase will vary depending on the style of your mission. (In some jurisdictions a paintball gun/marker may be considered carrying a weapon in commission of a crime.)
If you have been discovered, you will need to get out - fast. The quickest way to clear an entire building is to activate the fire alarms, either by holding a lighter to a smoke detector, or smashing an alarm, then just slip into the nearest crowd and walk out. This method will attract a lot of attention when a fire is not discovered anywhere - however, by then you can be far away, with ease.
For a less dramatic exit, simply head to any of the three possible exits you memorized earlier, and slip out when nobody is watching you. Claiming you are going for a cigarette is a great excuse, and nobody will notice your failure to return before at least five minutes have passed.
If you cannot have a getaway car and driver of your own running outside, notify a brother or sister in advance, so that upon receiving a phone call from you they can arrive outside of the building and collect you. If timed well, this particular method of escape can be pretty effective - you can usually escape a long time before your actions are discovered, and even longer before the pigs arrive.
If you are are discovered and trapped, your only other options apart from surrendering can become life-threatening. While dangerous, heading for the roof will help you get extra time, and can also get you a better view to consider your options.
If there are any nearby buildings, and you have packed rope and a grappling hook, you could attempt to use the rope as a zip-wire to get across; however, this is hard enough in a group, and by yourself this would be extremely hard to pull off. This technique requires between thirty and fifty pounds of specialized rope gear and lots of training. Rope rescue and technical climbing training is very useful in the event of an unexpected "Spider-Man" type getaway.
Another much less risky method of escaping using rope is to tie one end of the rope to something extremely secure at the top of the building, say a few prayers if you're religious, and abseil down the building. Remember the rope is your life at this moment, and you are taking a calculated risk if you don't use the correct safety equipment, but there isn't always time. For this method to work, you are probably going to need to create a distraction of some sort (e.g. letting off a very large smoke device or having friends chuck a few pepper gas grenades near the cops to tear their eyes up) and immediately begin to run when you hit the ground. If you need to abseil, leave the rest of your equipment behind.
When planning for a roof abseil/rappel escape at a minimum wear a self rescue belt(look in a rope rescue catalog), a descent device of your choice, and some 5mm spectra cord at least ten meters longer than the building. Look for an anchor that will take at least a ton of pull use a loop at least a meter in length and tie a figure-eight follow through knot. Use your jacket or other thick clothing as edge protection anywhere the rope hits concrete, army surplus firehose is the best edge guard but heavy. Don't ever use hardware store rope, it might just break when you are on it. Anything less than UIAA certified climbing rope, carefully inspected for cuts and dents, is unacceptable for situations where your life is on the line.
Depending on the height of the building you are in, and how close the surrounding buildings are, you can attempt a running leap; however, the chances of the distance and height allowing you to pull this off are very slim, so always be sure you can successfully pull off the jump. Even with a running start, it's unlikely you'll make a jump of more than six or seven feet. Mistakes will get you killed, so this is not an escape method to be used lightly.
See more escape in S.E.R.E.
Urban Exploration Resource http://www.uer.ca/ has many good forums and data on inflitration of various closed areas