True story: A couple decades ago the City of Detroit bought a couple parcels of land downtown to build a parking garage. They never combined the parcels with the county, though, so one looked like it was still owned by a private entity. A few years ago the county got their act together and started foreclosing on landowners delinquent in their property taxes. The city of Detroit ignored the mail about the property taxes being due. The county put one of the parcels of land for the parking garage up for sale, and a sharp-eyed investor bought it. The investor is now asking for half the revenue of the parking garage, as he owns half of the land that it sits on.
The city is, of course, taking the investor to court, but they don't have much of a leg to stand on, considering:
1. They screwed up the registration of the property in the first place
2. They ignored the tax notices
3. They ignored the foreclosure paperwork
4. They ignored the notice of sale for the auction