The most splendid example of stupidity I have ever seen is the security guard who decided to rob the shop he worked in and didn't change out of his uniform first which had his name on it. He was caught on the CCTV in the shop. Now that is stupidity - saw it on a program called something like Worlds Stupidest Criminals.
I've been trying to find the story on google but I can't at the moment.
There was a guy who carried out an armed robbery in a CCTV store in Manchester. That's got to count fairly high on the stupidity scale.
Then there was the chap who broke into a shop I worked at twice in a fortnight. First he broke in just to check a) If we had any cameras, we didn't & b) to see which windows weren't covered by the CCTV cameras in the precinct, he found one. Smart so far. Then a fortnight later he broke in through the correct window, but cut his leg on the glass, undeterred he rifled through the shop, taking a few grands worth of gear, then went home, leaving a very nice trail of blood for the police dogs to follow.
Totally-braindead, I saw that one and it was quite funny. It was called America's Dumbest Criminals I think and they had this other guy on there who did a raid with a bag over his head - but he forgot to cut the eyeholes out and ended up bumping into everything. This GPS theft tale also made me smile. GPS means Global Positioning System, so why would they leave it on when it was obvious they could be traced...madness. They also thought they were mobile phones. They must have thought they were old mobile phones as the phones nowadays have colour screens and can play the Crazy Frog whenever someone phones you. :-D