I suppose the amount of effort to get this stupid site drop Alrot's files would not be worth the result. I'm a bit pessimistic here but as many already said, Alrot is not the first one to get problems with that famous site.
After all, there is a reason why FSPlanet is nicknamed "FSPirates" on all the FS forums.
I think that's part of the solution. It's not just Alrot who has been affected, so it's more possible to drop the site instead of just the files.
As I said earlier, contacting the actual web host and informing them, and having the group support of those affected, would be an easier solution. It shouldn't have to come to a court case. If they downloaded a few of them for themselves they could probably see 'these websites only' or 'no fsplanet' in some of the READMEs. That should be proof enough.