The Chicago Police Department website is down, and "hactivists" from the group Anonymous are taking credit. It's part of a protest in Chicago against the NATO summit, where U.S. President Barack Obama is meeting with world leaders.

Activists are protesting NATO's policies, holding signs such as "War (equals) Debt," and "NATO, Go Home." Members of the hacker group Anonymous, calling themselves "AntiS3curityOPS," posted a video on YouTube with an ominous message to the Chicago Police Department, but that video has since been made private. We added a full transcript of the video to the bottom of this post.

In the bold video manifesto, the group responded to what it perceived as police brutality against the protesters on Saturday night, and vowed to take action:

"We are actively engaged in actions against the Chicago Police Department, and encourage anyone to take up the cause and use the AntiS3curityOPS Anonymous banner. For those able, chicagopolice.org should be fired upon as much as possible. We are in your harbor Chicago, and you will not forget us."

Police are investigating the possible hacking of the city of Chicago's website, according to the Chicago Sun-Times. Law enforcement officials told the AP late Saturday they planned to arrest people committing violent acts. Said police superintendent Garry McCarthy, "If anything else happens, the plan is to go in and get the people who create the violent acts, take them out of the crowd and arrest them. We're not going to charge the crowd wholesale — that's the bottom line."

At press time, the site, CityofChicago.org was still inaccessible. According to Cyber War News, the Anonymous group also claimed to have taken the NATO website offline, but it was accessible early Sunday afternoon.

Here's a transcript from the Anonymous video that has since been removed from YouTube:

Greetings fellow citizens of the world. We are AntiS3curityOPS. While this has come to no surprise, the NATO protests are already reaching a boiling point. As tonight we have already witnessed the Chicago Police Dept sending out a request for two water cannons deployed on Michigan Avenue, which the protesters briefly were able to close off the street completely. Just a few moments ago we witnessed cops on horses seemingly all too content with the destiny that has turned their hearts cold, trampling over protesters trying to intimidate. And you know what we saw during this? Protesters locking arms and holding their ground. A few had Anonymous masks on, a few were girls who looked like they belonged safely off on the sidelines bravely charging cops with shields and on horse. All the while the protesters are chanting “Take those animals off those horses,” drowning out any attempts by the Chicago police to get a word in. Everyone of you are heros to us. What we saw tonight watching a bit of the protest was everyday, average people fighting back and finally refusing to stand down. The NATO Summit is being utilized in such a way, and we couldn’t have predicted it more accurately. On the video we saw mothers, teenagers, elderly, the anarchists, white, black, Hispanic — this movement sees no skin color. Every sort of person is well represented in these actions. This is not a time to have our differences divide us; this is a time we all need to come together and rally around our brothers and sisters bravely in the streets of Chicago risking their lives to make the one voice they have, heard. If every single one of us has a voice, one opinion, let us unite and show the violent Chicago police, and the government big brother tactics that we are not going to take this. We are actively engaged in actions against the Chicago Police Deptartment, and encourage anyone to take up the cause and use the AntiS3curityOPS Anonymous banner. For those able, chicagopolice.org should be fired upon as much as possible. We are in your harbor Chicago, and you will not forget us. So for those unable to engage in attacks online by ddos, share with everyone you know what’s presently going on in Chicago, Tweet celebrities on twitter with the #SolidarityWithChicago #FuckNATO #FTP hashtags and get it trending. Also keep watching the live feeds, and spreading the live feed links all relevant places. Together, we the people, are going to take the power back. We are AntiS3curityOPS. We are Anonymous. We are legion. We do not forget. We do not forgive. Chicago Police Department, expect us.

Images courtesy of Flickr, gaelx