The best thing about these kinds of contests is they draw all the cheaters & alt accounts, making them easy to identify.

I know the contests are born out of purely good intentions, but as we've seen also with the pizza and art contest (as well as all the price prediction contests & free raffles), they attract a lot of users without consciousnesses. Anything that has to do with money will attract scumbags who won't respect the rules -- that's just how its always been, long before bitcoin.