Can confirm (source: I have a friend that works for a three-letter agency). Before I sit for a clearance interview, I asked him about it. I used to think I'd probably be disqualified, but I learned that was not the case at all. Much of what they're trying to determine is your exposure to potential blackmail.
How recent? Posts like "FBI can't find hackers" have been frontpaging for years but people who have responded to the ads say they were dismissed at the clearance step or advised to not continue due to it.
