Netball, Football, Hockey and Rugby (some UoM, some MMU) from what I have heard on the (very reliable, in this case) grapevine, although they tried to pin it on SKUM (skiing). Apparently it wasn't as bad as the papers have made out though.
I won't be impressed if the ferry companies permanently ban student groups from using the ferries though - if that happens, then the stupid actions of a small minority will cost everyone an awful lot of money.