I have a friend who uses an electronic key fob to enter and exit his apartment building. The fob isn’t metal, but it grants access electronically.
He occasionally engages in private activities.
My question is: Does this key fob log every entry/exit? He’s cautious with cell phones and leaves them at home, but wonders if the key fob could potentially cause problems.
Yes it can.
The fob has no idea what it has access to, in most systems it just has a serial number. When you tap it on the reader, the reader scans its serial number. The system has a list of which key numbers are allowed to open which doors at which times, if your key matches it opens the door. These almost always have some kind of log of which key opened which door when. Whether the building management knows how to access that is anyone’s guess.
If he loves in a building with fobs there’s probably cameras also.
So if he’s worried about after the fact investigation into his movements, he should live somewhere else.