…attacks against the U.S. Defense Department led to a compromise in 2004 (?) according to this article from August this year (via InfoSecurity News):

"The number of attempted intrusions from all sources identified by the Pentagon last year totaled about 79,000, defense officials said, up from about 54,000 in 2003. Of those, hackers succeeded in gaining access to a Defense Department computer in about 1,300 cases. The vast majority of these instances involved what VanPutte called "low risk" computers."

This also means that 1.6% of attacks are successful. Could be useful to start thinking about how to measure your own organization.

[Found this while refreshing my memory about Titan Rain, in reaction to the completely circumstantial assertion by SANS that the Chinese military "must" be involved in hacking US DoD. I don't deny the possibility, I just chafe at the FUD without evidence (unless, of course, there is evidence, which I am trying to dig up). More later.]