NBC suffered a Guy Fawkes themed hacking attack over the weekend by an individual (or group of individuals) running under the name, "Pyknic."
According to a report from Deadline, the site defacing began under NBC's portal sites for Saturday Night Live, Late Night with Jimmy Fallon, and The Tonight Show with Jay Leno. The attack eventually managed to make its way to the main NBC page, however, and numerous portions of the overall site were down (or defaced) for hours.
NBC's videos page was completely taken over, replaced with a looping audio clip in the background and the following text repeated numerous times: "REMEMBER, REMEMBER THE FIFTH OF NOVEMBER, THE GUNPOWDER TREASON AND PLOT. I KNOW OF NO REASON WHY THE GUNPOWDER TREASON SHOULD EVER BE FORGOT."
Additionally, the site's attackers claimed to have stolen user names and passwords from NBC's site, but NBC hasn't officially verified the these claims, nor suggested which of its users might be affected if the attackers' claims are actually true.
According to BetaBeat, "Pyknic" – or at least, an attacker or attackers posing as the same NBC hacker – also ended up defacing a popular Lady Gaga fan portal, gagadaily.com.
While the images and messaging thrown up on the NBC and Lady Gaga sites might indicate that Anonymous was behind the attack – given that the Guy Fawkes mask and related messaging are often used as symbols of the hacktivist group – there's no indication so far that Anonymous has claimed credit for the attacks on any of its usual communication channels.
There's also no indication that there was an overall message or motive for the attacks beyond annoyance and simple defacement. Happy November Fifth?