SAN FRANCISCO -- San Francisco prosecutors Tuesday charged a city worker with illegally tampering with the city's computer network, potentially exposing the information of both city workers and anyone who does business with the city.

Police arrested 43-year-old Terry Childs, a network administrator for San Francisco's Department of Telecommunications and Information Services, over the weekend, according to the San Francisco District Attorney's Office.

According to District Attorney Kamala Harris, Childs is believed to have disrupted the city's FiberWAN network system between June 20 and July 10. He was arrested on Sunday at his home in Pittsburg and is being held on $5 million bail, she said. Childs is a network administrator with the city of San Francisco's Department of Technology. He works in an office in One Market Plaza.

At a news conference in San Francisco Monday afternoon, Harris was vague about the facts or motive behind the sensitive case, citing an ongoing investigation.

Harris said the charges relate to "rules about accessing our computer systems and about who has authorized or unauthorized access to those systems."

According to Harris, Childs is believed to have temporarily denied services to authorized users on the network, and to have set up devices that would allow a user to gain unauthorized access to the network.

The network contains information relating to the city's 311 customer service center system, the city e-mail system and the city server, including "potentially" confidential private information, Harris said.

The door to Childs' part of the building is currently off limits, and officials in the office were saying that even his cubicle is cordoned off.

The San Francisco Chronicle is reporting that Childs is a disgruntled employee who basically hijacked the system so no one else could access it. Although Childs was reportedly a disgruntled employee, whose supervisors had previously tried to fire, the D.A. says she doesn't know what prompted the cyber hijacking.

"We don't necessarily have to know why he did it. What we have to do is prove what he did," said Harris.

The FiberWAN system connects the servers from all of the city's departments and is responsible for 60 percent of the network traffic of all city government, according to the District Attorney's Office.

Childs has been charged with four felony counts of computer network tampering, as well as one count of causing losses of more than $200,000, resulting from the tampering, the District Attorney's Office reported.

He is scheduled to be arraigned on the charges in San Francisco Superior Court on Tuesday at 9 a.m.

If convicted, Childs could face up to seven years in state prison, Harris said.