If you're talking about an online tournament, we have had them. Pretty much every time someone submitted an entry, the rules were not followed. And when a winner was selected, some members thought the one selected was not bigger than theirs, and so on and so on. When it's a public contest, there are lots of judges, and slightly bending rules or not being exact in the angle of the photo creates complaints. Especially when there is money involved. I'd rather have objective photo contests and give away sponsors prizes free.

And as G said, real life "at the launch" fruit jar type tournaments are held all over. Organized by members. Check in your state.