My personal favorites are the offices that require some sort of card/keypad/technical approval to go through in one direction, but have a motion sensor to unloc

My personal favorites are the offices that require some sort of card/keypad/technical approval to go through in one direction, but have a motion sensor to unlock it going the other way. I've gotten past these with a manilla folder (push through, it unfolds and triggers), and I've been told (untested by me) that motion sensors rely on bouncing an infrared beam, so they can be triggered by anything that makes a temperature change, such as a can of compressed air. Relevant XKCD: https://xkcd.com/538/ https://xkcd.com/538/