This one is an oldie but a goodie.
Basically through outsourcing the outsourced outsourcer's outsourcer, counterfeit Cisco equipment has made it's way into US Government infrastructure. There's not much you can do about a backdoor built directly into the firmware/hardware you use. I suppose the moral of the story is to use hardware sourced from reputable partners and download IOS files from Cisco instead of torrents.
The story is here









