In the U.S. House of Representatives seemed straightforward enough: government computers must block downloading porn.

After all, a series of news reports have highlighted,how some financial regulators earning six-figure salaries were watching porn at work as Wall Street imploded.

But the exact wording of the legislation (PDF) that the House approved last week by a 239-to-182 vote could, civil libertarians warn, go too far and unreasonably infringe on Americans’ First Amendment rights.

The measure, which arrived in the form of an 111-page amendment sponsored by House Appropriations Chairman David Obey, a Wisconsin Democrat, says on the second-to-last page: “None of the funds made available in this act may be used to maintain or establish a computer network unless such network blocks the viewing, downloading, and exchanging of pornography.”

“It really is breathtaking how broad the reach of this is, and will lead to constitutional problems and economic problems,” Morris said. If a mom-and-pop business has a contract to deliver toilet paper to a military base that includes overhead, he suggested, they’d have to pay to filter their computer networks even though the owner is the only one who uses it.

The ACLU is no less critical. “The Supreme Court has made clear that government attempts to eliminate sexually explicit speech on the Internet raise serious free speech concerns,” said Laura Murphy, director of the ACLU’s Washington legislative office. “Congress should not pass such vague and potentially speech-restrictive provisions that are constitutionally suspect.”

Ellis Brachman, a spokesman for Rep. Obey, not respond to requests for comment on Thursday. No hearings appear to have been held on how the porn-filtering requirement would be implemented.

Antiporn groups,

“I don’t think the courts would have a problem with it,” said Tom McClusky, vice president for government affairs at the Family Research Council. “I think they would view it as constitutional.”

Trueman said he has not had a chance to review the appropriations bill. He added, however, that the legislation would be more constitutionally problematic if the government says in order to get a contract, a business “must filter out all porn for all employees–even those not on a government contract.”

One argument that antiporn groups have in their favor is the history of the Children’s Internet Protection Act, which Congress enacted a decade ago also as part of a must-pass bill to fund the federal government.

The ACLU and the American Library Association sued, claiming that CIPA was unconstitutional. But in a 6-3 decision, the Supreme Court upheld the law, saying that while buggy filtering software could block legitimate Web sites, library patrons have the option to ask that it be disabled. (That requirement, part of CIPA, is not part of Rep. Obey’s legislation.)

On the other hand, the Obey bill uses the term “pornography,” which is not as specific as the legal terms used in CIPA. Salon.com has proudly featured not-quite-safe-for-work photographs; should the government’s filters deem them news, art, or porn?

Cris Logan, director of communications for the venerable anti-porn group Enough is Enough, says her group is familiar with and supports the Obey amendment, which is now awaiting a vote in the Senate.