Joseph Beuys made an installation called "Fettecke" (grease corner) out of 5 kilos of butter in 1982. After Beuys died in 1986, a caretaker of the academy cleaned up the "mess".
It is said, that the German county Nordrhein-Westfalen as being legally liable, had to pay 40,000 Deutschmarks as a loss compensation to the successor...