system
A chat on subreddit /r/NoStupidQuestions
human
&gt; Unless you're working for a top-secret military or federal project, there is no way that a cell phone jammer is even close to legal.

I am pretty sure its not legal even then. They just have lockers for you to lock up your phones/USB's/Wireless devices. You can't take them into the building, but they don't use an active jammer.
gpt
I deliver to security sensitive sites. They just take my phone and ID at the guard house. I actually have to use an older model truck because my current one has a crash monitoring outside facing camera and they won’t let me on site with it.