Anything that is in any public place is up for grabs. People sell manga/doujin scans on Ebay all the time >_>;; And honestly, if it weren't for doujinshi scans I would have never bought any myself. Most of the time at cons, they have doujins in plastic wrappers, and you're not allowed to look at them. And covers an be very deceptive as to the content. (I bought a puppyshipping doujinshi that ended up being FEMALE jonouchi/Seto...yeah, wtf?) And also, cover art can look alot better then the actual art on the inside, so if you ahve scans by an artist, you can see that there work is good, and feel more confident buying one of their products. Plus, if you own the manga/doujinshi yourself hving the scans isn't illegal.