The small crew of hackers who attacked the City of Mobile this week have a history of targeting police departments in several states and have released private sensitive information of Wall Street bankers, including former United States Treasury Secretary Robert Rubin.

On Friday, hackers associated with the loosely organized hacktivist collective Anonymous revealed that they had broken into City of Mobile computer systems where they obtained sensitive information, including names, social security numbers, dates of birth and other data, for 46,000 people. In a post on pastebay.net, a site that allows unimpeded ability to post text and code, the group said that its action was in response to Alabama’s toughest in the nation immigration law, HB56.

“We at the Cabin have been monitoring your recent racist legislation in an attempt to punish immigrants as criminals,” the post says. “The authorities in the state of Alabama are now able to question people suspected of being in the country illegally and hold them, and officials are able to check the immigration status of students in public schools. We will not idly stand by as this happens.”

CabinCr3w's Twitter avatar.

The authors signed the PasteBay post with three Twitter handles — @ItsKahuna, @CabinCr3w and @AnonW0rmer – and on Friday Weld for Birmingham reached out to them on Twitter. Friday afternoon, the hackers offered Weld an interview via irc chat. You can read a full transcript from that interview here.

Defining what is and isn’t Anonymous can be like nailing Jello to a tree. The group has no formal structure, no organization charts and no official membership. Wikipedia calls it an Internet meme — a contagious idea or belief structure.  It has no trademark, but to crib from marketing jargon, it has a brand: Computer savvy anarchists who make trouble for authorities. Anonymous first became an object of public fascination when the group declared war against the Church of Scientology. More recently, Anonymous has given its support to Wikileaks, retaliating against banks and governments that have tried to inhibit or kill the free-speech site. Mostly through DDOS attacks, anonymous has crashed websites for PayPal, the United States Justice Department and, on Friday, the CIA. It has been characterized as the “air force of the Occupy movement” and frequently attacks police departments after crackdowns on Occupy protests.

Anonymous’ portrayal in the media has ranged from knee-jerk fear-mongering to the somewhat incredulous. Regardless of how real Anonymous is, it is real enough to cause a lot of grief for authorities.

If Anonymous is the primordial ooze of hacktivism, crews are the self-assembling organisms that crawl from that pool. A handful of hackers will form over campaigns or projects, and can themselves be ephemeral.

(Some quotes from our interview Friday have been edited to fit the format.)

“Crews are like friendships , or cliques , but many are involved in many ,”  said AnonW0rmer, one the Anonymous members who hacked the City of Mobile servers. “Its weird , they are like groups but less permanent . Some crews form over operations, friendships or similar interests. Each has their own story.”

It was CabinCr3w that hacked into the City of Mobile’s servers. The crew has at least four members — AnonWormer, NASDAQEnema, Kahuna and MotorMouth — who participated in the interview Friday. CabinCr3w has been busy in recent months, attacking police department servers in several states and releasing personal data on Wall Street bankers, including former Treasury Secretary Robert Rubin.

In the interview Friday, the members of CabinCr3w emphasized first and foremost that they had deleted all of the data they had taken from the City of Mobile’s servers. In fact, the group says it protected the data better than the Mobile Police Department did.

A spokesperson for the City of Mobile told media Friday that the city had been warned by Utah authorities on Thursday that it could be under attack. The information taken by anonymous was not from the police department’s servers, but rather from Dogwood Productions, a web development company under contract to do Internet projects for the city, including an online calendar and an amnesty program for traffic violations.

The CabinCr3w hackers told Weld that the city has deleted the data but had not yet secured the entry point they had used to get into the system.

“I have had access to their databases since around the beginning of the week,” Kahuna said. “The information was all deleted overnight last night, but i had already pulled it off of their servers and had been doing so for days.”

The group has targeted police departments in many states as part of what it calls Operation Piggy Bank, but members said that they saw the Mobile opperation as an opportunity to draw attention to Alabama’s immigration law.

“OpPiggyBank is doxing and breaching police servers to bring attention social issues. We’ll go after cops who abuse their position, bankers who drop millions on NYPD, for examples,” NASDAQEnema said. “We mostly do documentation of public info but sometimes a new law or outrage warrants a reminder that police are human not come from on high. Mainly we do it to shame abuse, not threaten people.”

They have no intention of using any of the information for financial gain, nor are they interested in causing trouble for Alabama citizens, they said.

“There’s a lot of hyperbole and paranoia about our releases,” NASDAQEnema said.