The EULA I quoted and linked is Bethesda EULA for the Construction Kit found on the Steam Workshop. Since you have to get the CK through Steam, it's the EULA you agree to. The EULA IS a contract and is legally binding in most cases unless unreasonable demands are made, which isn't the case here. By agreeing to the CK's EULA during installation and modifying/adding to their game and distributing said mod you agree that THEY own said modification. It becomes their copyright and IP. The rest only says that they can do what they want with it, but it never states that they are limited to only those actions. They can even grant sub-licenses to companies they are affiliated with now or at any time in the future. They can order than any mod on the nexus be removed and destroyed at any moment, and Nexus would have to legally comply. The author of the mod would have absolutely nothing to say about it because they don't legally own anything. Again, Bethesda owns the rights. http://en.wikipedia.org/wiki/End-user_license_agreement http://www.osnews.com/story/23794/US_Court_Upholds_EULAs_Criminalises_Pretty_Much_All_of_Us To say someone can't use or update a mod claiming the author has rights when he signed away those rights is rather silly. People can use and mod everything else in TES, but you can't mod the mods especially those which are basically abandonware. You can be sure about it all you want. If there's even 1 single author not agreeing with you on this, a site making up such rules will be in legal trouble quickly. Firstly, if they cared at all, their mods wouldn't be abandoned. If they cared, they'd at least respond to PMs about letting someone else take care of it. Finally, As stated above, you can't sue over something you don't legally own the rights to.