They can just round up some friendly users and sue under their names. Starting with their own corporate accounts?
I'm not even sure he can use his own account as one of them. The SEC might be pretty friendly to him but I'm not sure that limiting access to a location where material information about Tesla/SpaceX is provided won't become a problem.
But I'm not even sure what damages the accounts are suffering as revenue sharing is going away [1]. With Bartz the damage is a loss of sale. With X the damage is $0 per post to the poster.
There is a newer Original Content Rewards program [2] but it seems to split revenue from X Premium and presumably people that have X Premium are not using XCancel so the damages would be 0.