Please read here about ripping :
Ripper Accusation TopicQuote
You MUST note the guidelines to this thread.
Resources offered over the internet, and thus, made public for everyone to use, have no labelled ownership.
Thus, an accusation based over these pretenses, ie., a signature created from the basis of a public render or stock will recieve no action in this thread.
However, a direct and identical copy would be considered a rip, provided it does not fall under the description below:
If you sell a piece of artwork to someone, you cannot claim exclusivity over that piece of material. That said, the person is free to resell the material, if he or she desires. They cannot, of course, claim author of said content, but they can resell or modify it further.