The group replaced the Texas Police Chiefs Association home page with one that listed police departments and officials whose email accounts it said had been hacked. The group posted a statement on the police website saying it was "attacking Texas law enforcement" because of the arrests of Anonymous supporters and what the group sees as harassment of immigrants by authorities in the state.
A telephone message left with the executive director of the Texas Police Chiefs Association was not immediately returned.
The loose-knit international hacking collective said the data it posted Thursday came from the work and personal email accounts of law enforcement authorities, including police chiefs. Most of the Texas law enforcement agencies that Anonymous claimed it had hacked into were police departments in small Texas cities or school district police agencies.
About 10 of the email accounts the group said it breached were personal accounts for law enforcement officials. Some of the individuals' personal information, such as Social Security numbers and passwords for various accounts, were posted online as well.
Some of the email accounts belonged to individuals who were retired from law enforcement.
The group said the information it posted online included classified police documents as well as lewd and racial jokes. A quick review of the large volume of data that Anonymous released Thursday revealed some of these things.
Robert Mock, one of the individuals whose personal email account was apparently breached, said he had only been made aware of the possibility earlier Thursday.
"I'm upset, as anybody would be whose account was hacked into," he said. "This wasn't my work account. Got my private information out there. I don't even know what's out there."
Anonymous listed Mock as being a lieutenant with the Houston police department, but Mock said he had left the department about four years ago. Mock said he still worked in law enforcement in the Houston area but declined to say where he was employed.
In addition to his cellphone and water bills, Anonymous also posted emails of jokes that were forwarded to Mock that made fun of Arabs and Muslims.
"I get forwarded emails like anybody else. I delete most of them. It is what it is," he said.
Another law enforcement official whose account Anonymous claimed to have hacked was Jesus Torres, an assistant chief of police in Laredo. When reached by a reporter Thursday, Torres said the call was the first he had heard about the apparent hacking and couldn't immediately confirm it had happened.
Anonymous also listed as hacked the personal email account of a manager of a Texas Department of Public Safety crime lab. Agency spokesman Tom Vinger said he had no immediate comment.
Last month, Anonymous claimed it hacked into some 70 mostly rural law enforcement websites, mainly from sheriffs' offices in Arkansas, Kansas, Louisiana, Missouri and Mississippi.