Strapping a magnet to a crocodile's head seems like two counts of animal cruelty for the price of one, just to appease old people in Florida who are racist against crocodiles in their backyards.
Florida state wildlife officials are taping magnets to poor crocodiles' heads when they catch them in people's yards or wherever they're not wanted (because people are racist against crocodiles, but for some reason not Crocs), even though they're gentle creatures. Magnets attached to the side of their heads throw off their internal navigational system, which it's believed is based on Earth's magnetic field, so the crocs don't return to where they're caught—which they do, normally, even if you take 'em a long way away. They'll move up to 16km a week to get back to where they were.
Personally, if people don't like crocodiles that much, I think they should send monkeys after them. I mean, Donkey Kong does pretty awesome against them, and then it's just nature doing its thing. It took him three tries, but I mean, there haven't been any of them for Donkey to deal with in a while.
Update for commenters complaining about crocs vs. alligators: Reuters is also reporting it's crocodiles they're strapping magnets to, not alligators, though that might be an alligator in the picture, which is from the Florida Fish and Wildlife website. And The University of Florida says there are crocodiles in Florida, they're just endangered (as the original article says, there are about 2,000 in the wild in Florida). [TC Palm via Slashgear]
P.S. I ate alligator once. Sorry if it was like your cousin or something Mr. Crocodile.