I would advise against it. You have no way to know where it's from (for all intents and purposes, "legit" implies it was actually SR'd etc, which you can't prove). I won't say you /can't/ put it in a thread if everything checks out, but if it turns out it's hacked you'll be held responsible. If you take the risk, please note that it's from the GTS, since some people will care.