Lord wrote:
The law is clear, if you are using them for non-economic purposes, then unless stated otherwise where you found the picture, you are allowed to use it.
I don't think it's quite that simple. Whether something is being used for commercial purposes is one of the criteria for determining whether it falls under fair use, but it's not the only one, and it doesn't definitively determine it one way or another.
Basically, I think Marcomage is so small that it's unlikely to get into legal trouble. However, just for the sake of principle, it would be nice to be using, if not original artwork, at least stuff that's licensed under creative commons or something.