Attorney General John Ashcroft (search) is so adamant about the need for the USA Patriot Act (search) that he will soon kick off an 18-city, four-week nationwide tour to explain the law to the American people.

Congress overwhelmingly passed the Patriot Act in the weeks following the Sept. 11, 2001, terror attacks. The Senate voted 98-1, the House 357-66. The new measures give law enforcement enhanced tools to fight the war against terrorism.

"The Patriot Act was a long overdue measure to close gaping holes in the government's ability, responsibility to collect vital intelligence information on criminal terrorists. It updated the law to accommodate modern technology such as cell phones and the Internet," Ashcroft said in a recent congressional hearing.

But some Americans and civil liberties groups say the law goes too far in curbing personal rights.

"We firmly reject the idea that the way to be safer from terrorism is to trade civil liberties," said Timothy Edgar of the American Civil Liberties Union (search). "We believe instead that the government needs to more effectively use the powers that it already had on Sept. 10."

Edgar said the new powers allow law enforcement to wiretap people and detain people while personal records are sought. Among those records are library checkouts, bookstore purchases, medical records and an array of other sensitive information.

According to a Fox News-Opinion Dynamics poll, 55 percent of Americans said they support the Patriot Act. But the ACLU is among a group of organizations that is filing lawsuits designed to chip away at portions of the act.

They are particularly concerned about what they call "sneak and peek" searches, or what the Justice Department prefers to call "a search with delayed notification" to the person whose property is being searched.

"The government can go into your home and search your home without notifying you," Edgar said. "Our Constitution requires you to get a warrant with probable cause to search someone's home or property or belongings."

In fact, the sneak and peek rules have been around for more than two decades. Ashcroft said law enforcement uses the measure on a limited basis, and it was redesigned in the Patriot Act to be used to infiltrate potential terrorist groups.

"Delayed notification is always done under the supervision of a federal judge," Ashcroft added.

Buried within a Justice Department appropriations bill that recently passed the Republican-controlled House is language that would end such searches. The Senate has not acted on the measure.

Ashcroft predicted that Congress will continue to support the Patriot Act. He said the nationwide publicity tour is designed to convince the American people that the war against terrorism is not over and neither is the need for the act's provisions.

Fox News' Brian Wilson contributed to this report.