[WalterBright]

I give it about 3 days before the students figure out they can "attend" class by giving the tag to their friend who is also taking the class.

The teachers will finally catch on when there is only one student in class, with 30 tags in his pocket :-)

[jawns]

I used to work in a high school where the students did something very similar. They needed their ID cards to reserve a computer in the library, and they'd have one kid collect multiple ID cards and make reservations for his friends, or they'd borrow each others' ID cards and hope we wouldn't notice.