If you hadn't heard, some radioactive material went missing in Mexico the other day. The first thing I thought was: Good thing the ol' border with Mexico is secure...
The radioactive material was something called Cobalt-60, and as far as I can tell, it seems to be some pretty scary stuff. You remember the guy who got his face melted in Radiers of the Lost Ark? It's that bad. This is the kind of material that could be used to make a "dirty" bomb. It's wouldn't have a nuclear reaction, but a conventional explosion would scatter radioactive material all over the place. Not a good scenario.
Also, by the way, here's a PROTIP from Permanent Press: Don't open things that have this marking on them. It's the international sign for "Don't touch".
The best news is that the Cobalt-60 was recovered, even though it was removed from it's casing. It seems like the thieves didn't know there was radioactive material there, and they weren't prepared to deal with it. Then they found it and took it out of the container, which was literally a weapons-grade stupid thing to do. So they're probably all going to die.
I'm sure the container had all sorts of scary looking radioactive markings all over it. Even thieves should know not to open radioactive containers, but apparently they decided to take a look. Now, they're probably dead in the desert somewhere.