1. Back channel communications and coordination between users.

2. User identities, including how many participating Reddit accounts are operated by the same individuals as alt accounts.

Basically, doing any effort to raise stock price beyond it's "proper" price in a coordinating way is a violation. Proving it is an entire another thing. I doubt this is what happening right now. I would like to see anyone trying to prove that ":rocket::rocket::rocket: GME to 1000" counts as such.

However, liability like that is why AMC is forbidden to mention in r/WSB by its name. It's easy to pump and dump that ticket.

This is why many "Let's take over this company with small market cap" threads were removed back in a day.