The alliance of conservative and liberal groups started a campaign against so called ``extreme provisions’’ of the USA Patriot Act that expanded the power of the law enforcement machine to conduct secret searches in the broadened framework of terrorism.

Ironically, the group, calling itself Patriots to Restore Checks and Balances, was headed by former Republican Representative Bob Barr. Mr. Barr voted for the law weeks after the Sept. 11 attacks but has become one of its leading critics.

The group urged Congress to modify the expiring ”extreme provisions’’, while President George W. Bush stands for its total renewal.

``We agree that much of the Patriot Act is necessary to provide law enforcement with the resources they need to defeat terrorism, but we remain very concerned that some of its provisions go beyond that mission and infringe on the rights of law-abiding Americans,’’ the group said in its letter to Bush, dated today.

The most aggressive criticism was pointed at the provisions which codified so-called ”delayed-notice’’ searches, in which the target isn’t immediately notified. The law also authorizes the FBI to demand “any tangible things’’ after telling a judge that they are needed for a terrorism or foreign intelligence investigation. Before the Patriot Act, the FBI had to meet a higher standard of proof before the judge.

Generally, the dispute reflects the increasing tendency of government to treat “every American as a potential suspect.’’