Not sure if this is the right place for this thread...

Anyway. I'm kind of paranoid, so I wanted to ask you guys. Naturally, I almost always need a reference when I make art. Usually, I use a photo. Now, if I sell that art, is the owner of the photo entitled to compensation? What has been scaring me is that, if I use a photo, make a sprite or whatever, and sell it to somebody to use for their game, I don't want it to come back and haunt me.