Originally Posted by Jeff Neese

I'll offer a counterpoint and say sure, go ahead and buy it. Any bike listed for sale has the potential to be stolen, and it's not your responsibility to make that determination. It's not like you're buying it out of the back of a van. It's listed publicly, and if you found it then so could the original owner and so could the police. You can't be accused of "trafficking in stolen goods" if it was publicly offered. Just save the original listing if you have any doubts. Go rescue that frame!