Hacktivist group Anonymous made the rounds over the weekend, attacking sites from CBS.com to (once again) Universal Music.

In what looks like hacking-spree retribution following the FBI's shut down of file-sharing site Megaupload, Anonymous didn't just take CBS.com offline on Sunday with a series of distributed denial-of-service (DDOS) attacks — it redirected visitors to different web servers all together. This means that visitors trying to access CBS.com saw what appeared to be a completely deleted site for about 20 minutes.

Anonymous redirected CBS.com visitors to servers that showed a directory file and error messages when trying to load pages. CBS.com is now back up and functioning properly.

The group also took down other sites over the weekend, including UniversalMusic.com — a site the group attacked last week — as well as its parent company, Vivendi. Various Brazilian sites were also involved in the cyber-attacks, including one for popular singer Paula Fernandes. Elysée — the official website of the French government — as well as several Polish government sites were also hit. Although Twitter accounts for The Daily Show and The Colbert Report were also hacked Sunday night, it appears to be an act from Anonymous supporters — not Anonymous itself.

Last week, the U.S. Department of Justice (DOJ) indicted seven people and two companies which ran the file uploading site Megaupload.com. The site — which called itself “the leading online storage and file delivery service" has been shut down for making $175 million on about a half a billion dollars in copyright infringement. Anonymous threatened in a video (above) to bring other sites down if Megaupload isn't reinstated soon.

The video states that Anonymous has gained access to the servers of the United Nations, Facebook, YouTube, Twitter and various banks, and threatened to take them down: "We are prepared to launch a global blackout of these websites" if Megaupload isn't back online in 72 hours. The video was released last Thursday.

"We have access to banking and credit card information of millions of citizens," the video said. "But as for the citizens, do not fear — for your accounts will not be compromised. This is simply to raise awareness — a demonstration to those that doubt our abilities. To those that support SOPA and PIPA. To those congressmen that want to vote yes on those bills. We are not f-ing playing. You have been warned."

According to a Huffington Post report, @ColbertReport and @TheDailyShow were also hacked on Sunday night, as identical tweets were sent out to followers with a link to this picture — two men in a disguise, one wearing a Pokemon hat. But the hackers said they were not associated with Anonymous, although they do support their efforts. The tweets also included hash-tags that referenced Anonymous and Stop ACTA!, a protest group of the anti-counterfeiting trade agreement. The tweets also included this message: "Watch your security, bro <3."

Soon after, the accounts reportedly tweeted followers to ignore the previous messages, implying that they had been hacked. Other Viacom accounts — including @ComedyCentral and @Spike_TV — were also hacked in the process through Hoot Suite, social media dashboard that helps companies manage and send messages to Facebook and Twitter.

The messages have since been deleted from @TheDailyShow, but @ColbertReport has left up a message denying ties to Anonymous: "We are not anonymous, however we do respect @anonops and @poisanon we are however http://twitter.com/ashpluspikachu <3 #stopACTA."

What site do you think will be Anonymous' next big target? Do you think Anonymous will ever be stopped? Let us know thoughts in the comments.

What is Anonymous? Check out the video below to learn more.