Celebrities including Beyonce and Jay-Z have had private details of their finances posted online.
Hackers have also put up information, but not credit reports, about US Vice-President Joe Biden and former Secretary of State Hillary Clinton.
Los Angeles police say they are investigating how a police chief’s private details, including his address and a credit report, ended up online.
Police Cmdr. Andrew Smith described the site as “creepy”.
He said: “People get mad at us, go on the Internet and try to find information about us, and post it all on one site.
“The best word I can use to describe it is creepy.”
Andrew Smith also confirmed that police would be investigating the posting of information about any celebrities living in Los Angeles.
Other affected people include Paris Hilton and Kim Kardashian.
Some of the private financial information posted includes social security numbers, which could allow fraudsters to commit identity theft.
Actors Mel Gibson and Ashton Kutcher are also reported to have been targeted on the site.
Information about FBI Director Robert Mueller is thought to have been uploaded. The bureau says it is aware of the site but has not revealed whether they will be investigating.
More names were added throughout Monday, including Britney Spears and former presidential candidate Sarah Palin.
The website uses an internet suffix assigned to the Soviet Union and includes some unflattering pictures of the people who are mentioned.
It did not state how it sourced the information but did include an anti-police message written in Russian.
One of the site’s pages also made reference to the former police officer Christopher Dorner who apparently committed suicide during a large scale manhunt, after he killed four people.
So far representatives for each person targeted either declined to comment on the accuracy of the information that was posted, or they did not return messages seeking comment.