On another forum some lawyers wayed in on the actually power of EULAs. The general idea is that they not very powerfull. The EULA apparently have even less power if you just quickly click agree/ok without looking at it at all.
Other laws could get them[modders] in trouble, like if some of their source code they distribute is just copied from the orginal, or stuff like that.
Companies just like to use the EULAs as threats with no follow through, if the EULA did have power, then they would have to have the whole agreement on the outside of the box, or be forced to give out full cash refunds to people who dont want to agreee to it.