Internet service providers must not release personal information about users in New Jersey without a valid subpoena, even to police, the state's highest court ruled Monday.

New Jersey's Supreme Court found that the state's constitution gives greater protection against unreasonable searches and seizures than the U.S. Constitution.

The court ruled that Internet providers should not disclose private information to anyone without a subpoena.

A Washington lawyer who handles Internet litigation, Megan E. Gray, said the ruling "seems to be consistent with a trend nationwide, but not a strong trend."

"It's contrary to what is happening with rights of privacy at the federal level," Gray said. "But it's all over the board for the states, with a mild trend toward protecting this information."

The 7-0 ruling upheld lower court decisions that restricted police from obtaining the identity of a Cape May County woman accused of retaliating in 2004 against her boss after an argument by changing her employer's access codes to a supplier's Web site.

Police obtained the woman's identity through her Internet provider, Comcast Corp. (CMCSA), by tracing an Internet fingerprint left by her computer. The fingerprint consisted of an Internet protocol address, often called an IP address, that could be identified only by Comcast.

Police obtained a subpoena for the data from a municipal court, but higher courts said a grand jury subpoena was necessary because an indictable offense was at issue.

Police must seek a criminal grand jury subpoena to get such information, the court found. And it said the woman's 2005 indictment on a charge of theft by computer cannot stand unless prosecutors have enough proof without the evidence, now suppressed, that they got from Comcast without having the right subpoena.

It was not immediately known how the Cape May County Prosecutor's Office will proceed. Prosecutor Robert L. Taylor did not return a message seeking comment.