NBC quickly restored several of its websites over the weekend after they were apparently hacked.

The Associated Press (News - Alert) said the individual or group behind the hacking was called  "pyknic."

There may be a link between the hacking and the well-known, hacking group Anonymous, TMCnet reported. It was reported that the websites from  Saturday Night Live, Jimmy Fallon and Jay Leno – as well NBC’s main page and its program directory were each impacted by the attack.

One report, after looking at the wording left by the hackers, suggested the cyber-attack related to Monday’s observance of Guy Fawkes Night, which involves an incident in 1605 when Fawkes was arrested with explosives in an effort to blow up Britain’s Parliament, Deadline Hollywood reported.

The AP also reported that "pyknic" attacked Gaga Daily, a fan site about Lady Gaga. That site was cleaned up quickly, too.

Anonymous has embarrassed companies, government offices and law enforcement by its repeated hacking.

For example, in February the hackers group was able to record a private meeting between the FBI and Scotland Yard, which was focused on the hacking group, TMCnet reported.  Later, Anonymous published the 17-minute conference call online for the world to see. It was posted on YouTube (News - Alert).

However, The New York Times was skeptical about the connection between Anonymous and the recent hacking of NBC news sites and the Lady Gaga site.“The main accounts associated with the Anonymous collective did not claim credit for the attacks on Twitter,” The Times reported on Monday.

Also, The Times said another recent rumored attack, on PayPal (News - Alert), never really happened.

“Members of the loose hacking collective claimed credit for dumping 28,000 passwords online that they said belonged to PayPal customers,” The Times reported. But the passwords belonged to ZPanel, a hosting site, The Times said.

Hackers also were rumored to have attacked Symantec (News - Alert) and several Australian government websites based on claims made on Twitter, The Times added.