Three years later, the Postal Service's lobbyists are fighting for Americans' privacy rights -- and opposing a bill in Congress that would allow U.S. Customs agents to open any internationally-mailed letter or parcel for almost any reason.

So far, the Postal Service has had little luck: On Wednesday, the U.S. House of Representatives approved the new surveillance powers by a 327 to 101 vote. The bill, titled the Customs Border Security Act, says that incoming or outgoing mail can be searched at the border "without a search warrant."

The vote on the larger bill -- which deals mostly with the budget for the U.S. Customs Service -- came after a surprisingly heated debate on the House floor over an amendment that would have deleted the mail-snooping sections.

"Exercise of these new powers could infringe on the right of innocent Americans to travel and communicate internationally free of unnecessary federal control," says Rep. Ron Paul (R-Texas), Congress' most ardent libertarian. "Please say no to unconstitutional searches and unaccountable government, and say yes to liberty and constitutional government "

Under current law, it is already legal for Customs agents to open packages they deem to be suspicious.

Rep. Maxine Waters (D-California) sponsored the amendment, which also would have preserved the current legal status of Customs officers, who can be sued civilly for wrongful searches.

It failed. On a largely party-line vote of 197-231, with only five Republicans voting in the affirmative, the House rejected Waters' proposal and voted to keep the bill intact.

In other words, that retains the Customs Border Security Act's original language, which says a customs agent cannot be held liable for any type of search, including racial profiling, as long as the "officer or employee performed the search in good faith."

Last December, the House's previous attempt to pass the bill failed by a 256 to 168 vote. It was considered under a procedure reserved for ostensibly noncontroversial bills that requires a two-thirds majority.

Even critics of the Postal Service say the agency has -- at least in this particular legislative tussle -- been sticking up for privacy rights.

"While I have been publicly critical of the U.S. Postal Service for their poor overall record on privacy, I will admit that they have been consistent and resolute in their adherence to our Fourth Amendment protections against warrantless searches," says Brad Jansen, deputy director of the Center for Technology Policy at the Free Congress Foundation.

But, Jansen says, the politicking may be mostly "a bureaucratic turf battle with Customs trying to poach authority from the Post Office."

Customs boasts that it "is considered one of the most effective agencies at congressional" lobbying and says that the Customs Border Security Act "carries a great number of important legislative requirements for the agency."

Katie Corrigan, legislative counsel for the American Civil Liberties Union, says she was heartened by Wednesday's floor debate.

"They expressed concern that the bill would undermine individual privacy," Corrigan says. "With each step in the process, people become a little more educated. We hope that when it heads into (a future Senate-House conference committee), we can strip that section out."

Last December, the ACLU sent a letter to Congress saying that: "People in the United States have an expectation of privacy in the mail they send to friends, family or business associates abroad. The Customs Service's interest in confiscating illegal weapons' shipments, drugs or other contraband is adequately protected by its ability to secure a search warrant when it has probable cause."

In the Senate, a similar bill with identical mail-opening language is waiting for a floor vote, which is likely to happen as early as this week.

Democratic senators Jon Corzine (New Jersey) and Dianne Feinstein (California) are expected to introduce amendments to delete the mail-surveillance sections.

Other opposition to the mail-surveillance proposals comes from industry groups. The Direct Marketing Association says "this would be the first time since Ben Franklin created the Postal Service that seizure and searches, without warrants, of outbound international mail would be allowed."