I work on a University campus. Adjacent to my building is a bicycle rack, to which several bikes have been locked since the start of the academic year (end of August). It's clear that these bikes have been abandoned; they have not been moved in four months, and some of them have been scavenged for parts (missing tires, seats, etc.). Some of them, surprisingly, still have good, usable parts, including quick-release seats and tires that, inexplicably, have not been taken.
In mid-November, the University public safety department put tags on all of these bikes reading:
This bike appears to be abandoned and per Regents ordinance will be impounded. If this bike is not abandoned it must be removed within 15 days.
It is now late December; more than a month has passed since the bikes were tagged, but as of today they have still not yet been removed, either by their owners or by the authorities (although I expect the latter will do so soon).
At this point it seems undeniable to me that the owners have given up any hope of reclaiming their property. Would it be legal to help myself to them, or to any usable parts that remain? Or have they now, by virtue of the tagging, become the property of the local authorities? Would taking them be theft -- and if so, from whom?
Context: This is in Michigan, in the United States.