[Porsche-poor]

there always has to be one or two people who ruin it for the rest.

We did something sim. in a college history class. On day one he handed out a seating chart and had you fill in your name. He used that a the master for the rest of the term. Any blank spot was compared to the master and marked absent. It didn't take long to figure out any name could be used to fill in a spot, say Darth Vader. Then is was only a small leap to filling in the blanks for friends who were absent.