Here's a real one that defeated a modern multi-path network not so long ago, constructed with WAN paths over some antiquated link encryptors. it seems that there was an undocumented (at least to the end user) "drop all keys" bit sequence. Now being a link encryptor this was parsed for within the flowing data stream, now one day an unassuming jpeg file attached to an email just by absolute chance (the bit sequence didn't have a lot of entropy to it) contained this bit-sequence, - instant denial of service attack as each link dropped, network re-converged and the still extant tcp connection between mail servers resent the offending packet until the site in question had completely isolated itself from the network. (that was a real doozer to figure out what had happened!)

This Dilbert came to mind...... http://dilbert.com/fast/2011-09-16/

Replying to myself, as I forgot my login details briefly. Sky tv set top box crashed precisely at midnight (was sadly watching the newyears TV stuff. Had to switch over to the old fashioned arial to watch the london fireworks. Did this happen to anyone else (thinking unlikely to find many people willing to admit watching the newyear on tv!) (personal excuse is having a young child!)