Though I am sure someone with direct knowledge will post, from my USNA experience, fake IDs are used - yes - by the self-same mids and cadets who write glowing essays for admissions and take oaths - usually for the purpose of under-age drinking. This is not looked on lightly, as a mid or cadet is essentially lying about their age, mis-representing themselves and acting in a way that discredits their service. It may be handled as an honor or conduct issue.
I will be interested to hear how the Amnesty Box is used and whether it has turned out to be a good approach.
It was never pretty when a USNA mid, faced with consequences from a conduct hearing for an alcohol offense, and an honor hearing for the fake ID, made that call home to mom or dad about why they wouldn't be home for the holidays, spring break, etc.
DS is now a plebe. He told me that on I-Day there was a curtained-off spot inside which there was a trash can that was labeled something like "fake ID amnesty". The idea was that each new plebe had to go in and that was their chance to deposit their fake ID with no consequences. If it were discovered after that, big problem. The idea of sending everyone in was to preserve anonymity of those who deposited a fake ID. It never made sense to me that a new plebe would even bring it with them to I-Day, but apparently some always do.
DD said that it is exactly that, a box to put fake ID's in if you had one; although I don't know why someone would bring it to in- processing unless they forgot that they had it on their person.