Yeah, I thought that too.
That's one lesson from the horror story column.
I also had a friend who bought a 3 story 12 unit apartment building. Had a renter who went without paying several months. the last thing this guy did before leaving was pour several bags of quick-crete down the drains and toilet. That just about broke him. everyone had to leave, and the repair was well over $10K.
But, as I said, I have had great renters. Seems like during the hardest part of the recession is when I had the dirt bags.