I do not believe that's provable and thereby enforceable.
How do you prove that there has been planning out-of-game?
No, not easy to enforce. It can be provable: if you see lots of people acting in coordination, Tom can check their messages (someone please correct me ASAP if I'm wrong). If he sees that they're not sending messages that explain their actions, but still engaging in non-random activity... OOG coordination.
