So we've all heard the "there is a bike locked up in front of my house/work/apartment with its (insert components) missing" should i cut the lock and "save" it thread. Here is my scenario though.

A bike mysteriously appeared behind my work this evening leaned up against the fence in the back parking lot. Its chain is off the rings and otherwise seems ok. It has been sitting there for +/- 6 hours now. My assumption is that this bike was stolen elsewhere and then abandoned there when the chain fell off. So my question is should i snatch it up and post adds in CL for the bike as found and hope to find the owner, but if no owner is found keep it as my own?
Or should I just leave it there for either someone else to steal that will probably not have as good intentions as I, for the theif to return and re-steal it, or for what is probably the least likely scenario that the original owner left it there and he/she will return to get it.

The bike is NOT LOCKED and i obviously wouldn't do anything that I wouldnt want another fellow cyclist to try to do if my bike was stolen...

So should i "Save" it?