I was a TA at Princeton ~5 years ago, and I had forgotten about the honor code until reading this. Yes it's true, we did not proctor exams, and students seemed to take pride in it. On every test, you got the names/signatures of those sitting next to you. But also, I had a student who was accused of not putting his pencil down when the test had concluded, and the bureaucratic process to fight the accusation was so crippling that they had to take a semester of leave anyway. So I don't see harm in tearing it down.

Hm, this answers something I was wondering, how do accusations work with no proctors or other evidence