The hacker group known as Anonymous posted a video today, promising to destroy Facebook on Nov. 5, 2011. The group said the purpose of the attack is to revolt against Facebook allegedly selling or sharing information with governments, and the lax privacy controls Facebook offers consumers.

The group has claimed responsibility for successful attacks against Visa, PayPal, Bank of America and a host of governmental agencies around the world. The group denied responsibility for the recent high-profile attacks on the Sony Playstation Network, although it was often cited as the group behind the break-in.

Anonymous Threatens to Take Down Facebook

It’s unclear why the group would give such notice to Facebook, as Sean Ludwig at VentureBeat.com points out. One theory is that the group is identifying and recruiting sympathizers on Facebook — which has 750 million active users worldwide to pull from. It’s also possible the group has developed a Facebook virus intended to attract unsuspecting friends into bringing down the site.

One thing is for sure, you might want to consider downloading up your Facebook data if you’re a heavy user of the social networking service.

What steps — if any — do you plan to take?