Estimates pegged TD Ameritrade's initial security breach to, approximately, October 2006. Well, they were wrong. Network World got ahold of emails from a security expert to Ameritrade dating back to January 9, 2006. Valleywag commenter Snarkosaurus claims to have evidence that the online stock broker was hacked as early as December 2005. Not only does this mean Ameritrade was hacked almost two years ago, but the company has known about it for an equal span of time. The reason the company offered for not notifying the 6 million or so affected accounts sooner? It didn't know how the information was getting out, so there was nothing it could have done. If you work for Ameritrade security, apparently ignorance is bliss.