This Week In Ill-Advised Ideas: Feral Cats

Saw this story a few days back. Apparently Chicago's currently suffering from a sudden spike in its rat population. In an effort to wipe out this plague of vermin, the Tree House Human Society, a local animal shelter, has come up with the brilliant idea to release a thousand stray cats into the city.

Gosh, there's no possible way a plan like this could ever go wrong!

To be fair, the Humane Society assured everyone that the cats will be spayed and neutered, so there's no possibility of them multiplying. Still... has this strategy ever worked? What happens when the rats are gone and they need to get rid of the cats? Release packs of coyotes downtown?