This entire convention likely makes DoHS wet their pants.
BTW, the MBTA hack news made Google News front page. MBTA is probably having frantic meetings, with some completely unqualified, but six-digit-paid appointee of "DeVille" Deval Patrick or Mumbles Menino having a Very Bad Day.
Good.
If you want to laugh your fourth point of contact off, see the other Defcon thread.
DHS did have representatives at Defcon. Yes, they were spotted as part of "Spot the Fed" competition. Several government agencies did send official representatives to give speeches at Defcon, all of whom did excellent work. They also had a Q&A panel, where hackers had an open forum for discussing any and all issues with a multitude of feds.
The issue that should have DHS pissing themselves is the state of SCADA networks. Think the security of the Internet in 1995. Only worse. And running every critical infrastructure in the US. It deeply worries me, and I usually am very skeptical. Don't read up on SCADA if you like sleeping well at night.