Artists keeping other artists from our store to avoid competition

Now, this is something I would not expect at all! Artists keeping each other out of our website to avoid competition! I just found out from one of our new artists that his buddy, who have been an artist on exchange3d.com for a couple of years did not tell him where he sells his models. Not only he did not tell him, he said, "I won't tell you", because he did not want the competition! So, the guy had to find out by himself, where his buddy was selling his models.