The CIA's public Web site is inaccessible this afternoon, and the hacking group Lulz Security is taking for responsibility for taking it offline.

Shortly before 3 p.m. PT, LulzSec tweeted: "Tango down - cia.gov - for the lulz"

And indeed, the world's most famous spy agency is currently without an official Web presence, as of about 20 minutes after Lulzsec's tweet--cia.gov returns an error message.

LulzSec has enjoyed a higher profile of late, thanks to a slew of successful attacks on prominent Web sites. In the past couple of months, the group has claimed responsibility for attacks against Sony Pictures, Sony Music Japan, and other Sony organizations. The group has also targeted Nintendo, Bethesda Software, and Infragard, a company that works closely with the FBI.

The group stepped up its activities this past weekend with an attack on the U.S. Senate's Web site that yielded access to the server's directory and file structure, the contents of which the group published on its own site.

The latest hack comes a few days after LulzSec began tweeting a phone number and encouraging followers to call in requests for hacks.

Apparently the group is bent on going after the spookiest of the spooky powers-that-be, but still has time for other side lulz, like taking down magnets.com and flooding the company's phone lines. "...we called them and they wouldn't tell us how magnets worked," the group explained in a tweet announcing the hack earlier today.