Since the beginning of the year, a new Pennsylvania law on public records has been sending tremors through state and local governments.

Unprecedented numbers of citizens, civic groups, reporters and businesses have filed thousands of requests for government documents and data.

Now come the aftershocks: Dozens of public-record lawsuits are piling up in courthouses around the state, waiting for judges to spit out rulings on what the law really means.

In Philadelphia, a retired police sergeant named Jihad Ali wants the names and salaries of everyone working for the Philadelphia Industrial Development Corp., the quasi-public agency involved in most of the city's big economic-development deals for the past 50 years. The state's Office of Open Records (OOR) says that he's entitled to the information, but PIDC is appealing to Common Pleas Court.

The Pittsburgh Tribune-Review asked for a spreadsheet of Pennsylvania projects funded with homeland security grants. The state's Office of Emergency Preparedness provided a 278-page list in a PDF format - but without the names of municipalities receiving the grants, or any other information on where the projects are. The newspaper is appealing to Commonwealth Court.

The Inquirer has asked for the home addresses of more than 20,000 city employees. The Office of Open Records says that the new state law establishes a public right to those addresses, but the city is appealing to Common Pleas Court.

The new law is more detailed than the old one in specifying which government records are open to the public and which are not.

It also created the OOR, a state agency to act as a first-stage arbiter when there's a dispute over a record being public or not.

In just eight months, the OOR has handled more than 4,500 e-mails and phone inquiries, about evenly split between people wanting to get information and government agencies wondering if they have to provide it.

The office has issued more than 450 written opinions. More than half the time, the office has ruled against the requester. But it has created a small firestorm of controversy with several rulings that would force public agencies to disclose the home addresses of employees.

The new law could be a victim of its own success.

As of yesterday, 55 rulings from the OOR have been appealed to local or state courts, where county and appellate judges will ultimately decide which government records the public is entitled to see.

There's a serious risk that when the cases are argued, John Q. Public will be legally outgunned by local and state agencies, using taxpayer money to pay thousands of dollars in legal fees - and arguing, usually, that taxpayers have no legal right to see the records they're asking for.

"That's one of the things we're concerned about," said Gayle C. Sproul, a Philadelphia lawyer and president of the Pennsylvania Freedom of Information Coalition, a nonprofit group that helped lobby the Pennsylvania Legislature to pass the new law.

The coalition has established a network of lawyers who are willing to provide free advice to citizens who find themselves drawn into a court case over a public-record request.

So far this year, county courts have ruled on four public-record cases, all relatively minor. But in all four, the judges ruled against public disclosure:

* In Tioga County, a judge overruled OOR, deciding that a local volunteer fire company is not covered by the right-to-know law and need not open its financial records to an inquiring citizen.

* In two Delaware County rulings, a judge denied requests from a New Jersey business looking for up-to-date information on local water bills and real-estate taxes, without paying special fees for certified records.

* In Montgomery County, a judge ruled that attorney Burton Stein had no right to find out who had filed a zoning complaint about the Germantown Pike office where he'd been practicing law the past 17 years. Stein suspects that the zoning challenge was inspired by someone who wants to buy the property.

Several bigger cases are pending:

* Local school districts and municipal governments around the state are appealing OOR rulings that the home addresses of teachers and other government employees are public record, to be disclosed to anyone who asks, unless there is specific evidence that a particular disclosure would jeopardize someone's personal safety. When the Legislature passed the new public-record law last year, it exempted the home addresses of judges and law-enforcement personnel, but did not protect the home addresses of other public employees.

* The city's longtime economic development agency, PIDC, is appealing an OOR decision that would force it to turn over payroll information to Ali, who has been monitoring the city's economic- development agencies since he left the police force in 2003.

PIDC contends that it is a private, nonprofit corporation not covered by any public-record laws. Its president, Peter Longstreth, says that private companies would be reluctant to seek PIDC's help if they had any concern that their dealings would be subject to public-record requests.

Apart from the litigation wave, the new law has been effective in requiring government agencies to identify open-record officers, setting deadlines for agencies to respond to record requests and providing recourse for requesters who get ignored.

"It's a whole different ballgame from what we were operating under before," said Mary Catherine Roper, a staff attorney with the American Civil Liberties Union of Pennsylvania, already involved in a series of public-record disputes with the state and the city.

The ACLU approached the Philadelphia Police Department early this year, looking for data on how the department deals with undocumented immigrants, and what happens when police stop pedestrians under the department's controversial "stop-and-frisk" program.

The department acknowledged receiving the request, but never delivered any data. After 30 days, the ACLU appealed for help to the OOR - which was also ignored by the Police Department. The OOR eventually ruled that the ACLU had a right to the data, and that the police were "willfully not complying."

Even then, the Police Department remained unresponsive, until the ACLU filed a lawsuit in Common Pleas Court.

Because of the OOR's decision, Roper said, there was a threat that the city would have to reimburse the ACLU for its legal costs.

"That's so much more leverage than we would have had under the old law," Roper said. The city is now working to accommodate the group.

"I think ultimately we'll wind up getting what they have," Roper said.