I have an idea for starting a business to do with modding.

I was thinking of setting up a website that would allow people to advertise and sell their mods and other works.

However, I'm concerned this may lead to issues about copyright, because people would be selling mods that would have some code or graphics that is already present in vanilla versions of games.

What do you think? Is selling a mod a copyright violation? I don't want to be assisting anyone in breaking the law.

Regards,

Josh