To be both on and off topic. Marvel a while back got very mad at a modding website called Skintucky Fried Sims for making multiple Marvel characters to use in the original Sims, so this was a LOOOOOONG time back. They were forced to remove any and all Marvel content from their site and so were just about every other site that had Marvel characters.
Now considering this is a different medium than digital art I think it might play out differently, seeing as one figure isn't the same as a massively available sim mod. Just to be safe though, watch out for the big companies if they ever start cracking down.
At some point I need to make a proper trading page.