BlackBerry Curve 9330 Sprint non-clean ESN?

Found this BB about a week ago in a rest room. I got a hold of the owner who hasn't picked it up. He said he would pick it up that day, but never did. I called again he didn't answer. MY assumption is, he no longer wants/needs it. I checked the ESN and it's not cleaning meaning the owner already reported it lost/stolen. If they're not picking it up, nothing I can really do about it right? I attempted to do the right thing. So activating this phone with Sprint is out of the window. Can I still unlock it to use with MetroPCS, or is this phone pretty much paperweight for me? If not I might eBay it for parts.