You just reminded me of a funny thing that happened with my test experience. They actually did have an 'Amnesty' plastic bag (the gallon size) sitting on the 3x3 desk when I arrived at my seat. The proctor instructed us to write our name on the white strip. then told us to put any unauthorized items in the bag which would be held by the group proctor.
I had nothing illegal with me, and when the early-20s female proctor came over to my desk, she said I was holding things up until I put my items in the bag. I informed her that I had none, and she gave me smirk'ie look and said, 'Well, phones are not allowed", to which I immediately replied that I had left mine in my car. She acted as if she didn't believe me, and came over two more times before we started and reminded me that I MUST turn my phone over to her.
After the test started, when I first reached for my TI calculator, she jumped up out of her seat and rushed to my table to see what I was using.
Finally, at the end of the morning round, as I head to lunch and walked past her desk, she looked up and said that I "caused her a 'lot' of extra paperwork." When I asked how that was, she said that not placing a phone in that bag raised a yellow flag.