U.S. District Judge Lowell Reed of Philadelphia wrote in his finding that he sympathizes with Congress and its desire to protect children from sexually explicit materials on the Web, but that the "flawed statute" neither protected rights guaranteed by the Bill of Amendments, nor was as effective as filters now available.

"This court, along with a broad spectrum of the population across the country, yearn for a solution which would protect children from such material with 100 percent effectiveness," Reed wrote. "However … I may not turn a blind eye to the law in order to attempt to satisfy my urge to protect this nation's youth by upholding a flawed statute, especially when a more effective and less restrictive alternative is readily available (although I do recognize that filters are neither a panacea nor necessarily found to be the ultimate solution to the problem at hand)."

COPA, created by Congress in 1998, was blocked from being enforced almost from its inception. However, the statute bounced around as the courts mulled it over the years. During that time, the U.S. Department of Justice subpoenaed search engines to get the Web addresses and records of searches as part of a study undertaken to determine how much objectionable material there is online.

MSN, Yahoo and AOL turned over the requested materials, but Google held fast and refused the government's requests.

The March 22 ruling is a victory for the American Civil Liberties Union, which had brought the suit against the government along with plaintiffs that included online sex health sites, San Francisco poet laureate Lawrence Ferlinghetti and the Electronic Frontier Foundation.

Paul Myer, president and chief operating officer of 8e6 Technologies, a maker of online content filter appliances and an authority in online child protection and filtering for school-aged children, noted that historically it's been "very difficult" to legislate morality as it relates to the Internet.

"More specifically, [regarding] some terms they use in the original act, it was an effort to legislate what content providers could make available and to whom," he said in an interview with eWEEK. "That's what's proving to be its undoing. You end up with enemies on the content provider side and the ACLU targeting you as well."

If legislation such as COPA doesn't get struck down, Myer said, it's still difficult to enforce. "We've seen legislation trying to legislate spam out of existence, but as it comes through, the amount of spam on the Internet goes up dramatically. Providers shift places where they send spam from, and they find ways around [the legislation]. They find that as spam is less effective, they have to send more to get the same hit rates. As the CAN-SPAM act was passed over last year, the amount of spam has increased dramatically. So a lot of times legislation doesn't result in the original objectives they had when they wrote it."