Several NBC sites were hacked over the weekend, in the run-up to Guy Fawkes' Night.
The sites included the pages for Saturday Night Live, Jimmy Fallon and Jay Leno, as well as the main NBC site and a Lady Gaga fan site, GagaDaily.com. All are now back up and running.
The hacker, who called himself Pyknic, replaced the pages with a text statement repeating the children's rhyme - "Remember, remember the fifth of November, gunpowder, treason and plot; I see no reason why gunpowder treason should ever be forgot."
There was then a reference to the Nigerian 419 scam - "Just a game" - and a warning that user information had been exposed and passwords dumped.
The Anonymous hacking collective had warned that it planned to carry out attacks Guy Fawkes' Night, but had threatened Facebook and Zynga - currently both still fine - rather than NBC. It's not clear whether Pyknic is a member of Anonymous.
November 5 also often sees Anonymous supporters taking to the streets to protest, wearing Guy Fawkes masks. However, in Canada, they'll only be allowed to wear them as long as demonstrations remain peaceful: the country's government has just approved a law banning people from hiding their faces during a riot.
"The bottom line is that the perpetrators who are criminalized by this legislation are not lawful protestors," said Alberta Conservative Blake Richards, who proposed the bill.
"We are not talking about giant pandas, Frosty the Snowman, as some members might suggest, or as members of the media talked about, the PETA seal. I am not looking to criminalize pandas, Frosty the Snowman or seals."