John Anthony Borell III, of Toledo, Ohio, was set for arraignment Monday in federal court in Salt Lake City.
The 21-year-old is charged with two counts of computer intrusion in a March 16 federal indictment unsealed Monday.
Prosecutors say Borell intruded on the chiefs' website server Jan. 19, then broke into the police department's website Jan. 31. The administrator of the Utah chiefs' website estimates the group spent $150,000 to mitigate the attack.
FBI investigators say they tracked Borell through his Internet address associated with a Twitter account he had been using to claim responsibility for the attacks. The indictment cites several Twitter messages between local media, including an Associated Press reporter, and the suspect using the screen name (at)ItsKahuna, in which he takes responsibility for the hacking.
Borell was arrested March 20 and has been detained in Ohio. Each count carries up to 10 years in prison and a $250,000 fine.
It wasn't immediately clear if Borell had an attorney.
The attack on the Utah servers came around the same time a spate of Internet attacks attributed to Anonymous occurred around the country, in Boston, Syracuse, New York, and overseas in Greece.
Saboteurs stole passwords and sensitive information on tipsters while hacking into the websites of several law enforcement agencies, police have said.
Authorities in early February had said the hackers who attacked the Salt Lake City Police Department website gained access to citizen complaints about drugs and other crimes, including phone numbers, addresses and other personal data of informants.
The police website was just recently restored after additional security measures were added.
Anonymous is a collection of Internet enthusiasts, pranksters and activists whose targets have included financial institutions such as Visa and MasterCard, the Church of Scientology and law enforcement agencies.
Following a spate of arrests across the world, the group and its various offshoots have focused their attention on law enforcement agencies in general and the FBI in particular.
At the time in February, Anonymous also published a recording on the Internet of a phone call between the FBI and Scotland Yard, gloating in a Twitter message that "the FBI might be curious how we're able to continuously read their internal comms for some time now."
In Greece, the Justice Ministry took down its site back in February after a video by activists claiming to be Greek and Cypriot members of Anonymous was displayed for at least two hours.
In Boston, a message posted on the police website before it was taken down said, "Anonymous hacks Boston Police website in retaliation for police brutality at OWS," an apparent reference to the Occupy Wall Street movement. The message also promised "there is plenty more mayhem to deliver."
