Dozens of NBC websites fell victim to hackers yesterday, in an attack that appears to be linked to the notorious cyber-hacktivist group Anonymous.

The hacker or hackers, who go by the name “pyknic”, defaced the websites with a long message making reference to Guy Fawkes, whose masks have long been something of a symbolic icon for the hacktivist group.

It appears that the hack was noticed right away, as ZDNet reports that the sites were cleaned up in less than two hours of the attack. As of this morning, NBC and its other websites now all appear to be functioning normally, although cached versions of the page on Google and Bing continue to display the hacker’s statement, and their signature “hacked by pyknic”.

The full message posted to the NBC sites read as follows:

REMEMBER, REMEMBER THE FIFTH OF NOVEMBER, THE GUNPOWDER TREASON AND PLOT. I KNOW OF NO REASON WHY THE GUNPOWDER TREASON SHOULD EVER BE FORGOT. REMEMBER, REMEMBER THE FIFTH OF NOVEMBER, THE GUNPOWDER TREASON AND PLOT. I KNOW OF NO REASON WHY THE GUNPOWDER TREASON SHOULD EVER BE FORGOT. REMEMBER, REMEMBER THE FIFTH OF NOVEMBER, THE GUNPOWDER TREASON AND PLOT. I KNOW OF NO REASON WHY THE GUNPOWDER TREASON SHOULD EVER BE FORGOT. REMEMBER, REMEMBER THE FIFTH OF NOVEMBER, THE GUNPOWDER TREASON AND PLOT. I KNOW OF NO REASON WHY THE GUNPOWDER TREASON SHOULD EVER BE FORGOT.
GREETZ TO ODAY, BRUT4L & S4VAGE
FUCK THE FEDS, 419 IS JUST A GAME~~
USER INFO – EXPOSED
PASSWORDS – DUMPED

The reference obviously suggests a link to Anonymous, whose supporters have often been seen wearing Guy Fawkes-style masks at protests and demonstrations. What will be worrying to those who have registered with NBC’s sites is if any of their personal information might have been compromised. It’s not clear if anything has, but the claim that user info has been exposed and passwords have been dumped will certainly be cause for further investigation.

Interestingly, a popular Lady Gaga fan site, Gaga Daily, was also hacked by the same group, compelling the pop diva to post a message of support on Twitter:

“My little angels! help is on the way. haus of gaga techies will be on it … to the rescue. calling them now.”

NBC will no doubt be concerned by the attack, as this isn’t the first time that they’ve been compromised. Just last year, the news broadcaster saw its Twitter handle @NBCNews hacked by the ‘Script Kiddies’ group, which posted a series of fake messages about 9/11 on the anniversary of those attacks.