On June 11, Sen. Ron Wyden (D-Ore.) temporarily blocked the renewal of legislation that allows the U.S. government to listen in, without a warrant, on Americans' conversations, so long as they're chatting with overseas chums who are the official targets of the eavesdropping. In doing so, Wyden not only stood against a bipartisan cabal of snoopy legislative colleagues, but also against the White House, which wants the extension passed and is vigorously battling against constitutional challenges to such electronic eavesdropping. That may come as a bit of a surprise to anybody who remembers then-presidential candidate Barack Obama promising to end the use of warrantless wiretaps that were so popular under the George W. Bush administration.

Strictly speaking, Obama didn't break his promise after he won the presidency; no, he managed that after sewing up the Democratic nomination, when he voted for the Foreign Intelligence Surveillance Act Amendments of 2008, now up for renewal. That legislation gave cover to a policy that was already in effect, but was illegal. So, when Sen. Obama voted for the FISA amendment in 2008, he joined his colleagues in supporting a bill that immunized telecommunications companies against the flurry of lawsuits they faced for collaborating with government snoops in their then-illicit activities. The law also "permits the NSA to intercept phone calls and e-mails between the U.S. and a foreign location, without making any showing to a court and without judicial oversight, whether or not the communication has anything to do with al Qaeda—indeed, even if there is no evidence that the communication has anything to do with terrorism, or any threat to national security," as Marty Lederman, of the Department of Justice's Office of Legal Counsel put it so well, before he took his current job in the Obama administration.

Now, you might think that the U.S. Constition's Fourth Amendment would put such at-will snooping off-limits, with or without legislation, but that's not the way the government reads it. Starting with the curiously named United States v. United States District Court of 1972, the Supreme Court has ruled that constitutional protections definitely apply to domestic wiretapping, but that "domestic security surveillance may involve different policy and practical considerations from the surveillance of 'ordinary crime'" and that foreign surveillance might be a different creature entirely. The feds have taken that little opening and very creatively turned it into a big hole—often by simply invoking the word "foreign."

Well ... Curious stuff indeed. But how widespread is this sort of surveillance?

Actually, that's one bit of information Ron Wyden is holding out for with his FISA Amendment roadblock. In response to that question, Kathleen Turner, Director of Legislative Affairs for the Office of Director of National Intelligence, responded, "it is not reasonably possible to identify the number of people located in the United States whose communications may have been reviewed under the authority of the FAA...." Oddly enough, that's an awfully close paraphrase of what then-Director of National Intelligence Mike McConnell said in response to a similar question in 2007: "I don't have the exact number. It is a very small number considering that there are billions of transactions everyday."

With "billions of transaction," we know that somebody is being scooped up in these wiretaps. We even know of specific somebodies because the federal government, in a miracle of official incompetence, accidentally spilled the beans. As the Electronic Frontier Foundation told the tale in 2008:

The Al Haramain case alleges that the Bush Administration illegally targeted the leaders of an Islamic charity and their lawyers for warrantless surveillance by the NSA. Their claims are based on a secret document that was accidentally disclosed to the plaintiffs by the government that the plaintiffs allege demonstrates they were subjected to warrantless wiretapping (the contents of the document are tightly sealed as a state secret).

The Bush administration is long gone, and the government has since legalized its warrantless surveillance, but the Al Haramain case lingers. It's now before the U.S. Court of Appeals for the 9th Circuit, where Justice Department attorney Douglas Letter, representing the current administration, told Judge Michael Daly Hawkins and Judge M. Margaret McKeown that the case should be dismissed because sovereign immunity shields the government from liability for its surveillance excesses. Reports Wired:

“I’m trying to understand the government’s overall position,” Hawkins said. “The government’s position is you can’t sue the government, you can sue anybody else, but who those people are might be a state secret.”

“Correct, your honor,” Letter said moments later.

Maybe a separate case brought by the American Civil Liberties Union will have better luck with the Supreme Court itself. With Amnesty et al. v. Clapper, the high court is set to determine whether the ACLU's clients, including Amnesty International USA, Human Rights Watch, The Nation, and the Service Employees International Union, have standing to legally challenge the eavesdropping going on under the FISA Amendments Act of 2008 that the president used to think was so terrible. The issue here, as the ACLU points out, is that "[t]he Justice Department claims the plaintiffs should not be able to sue without first showing they have actually been monitored under the program—but it also argues that the government should not be required to disclose if plaintiffs have been monitored."  Presumably, if the feds win the case, this means that we'll have to wait for some government clerk to, once again, accidentally mail the wrong documents to a surveillance target.

But isn't the government arguing in that other case that it can't be sued anyway?

This makes Sen. Wyden's lonely stance that much more poignant. Remember, the federal government's untested position is that the word "foreign" is legal kryptonite to the Fourth Amendment. To minimize the need to defend that position before the Supreme Court, it's doing everything it can to prevent people from knowing they've been snooped upon, and to make itself impervious to lawsuits if people do inadvertently discover the truth.

Which may leave nothing between our communications and government interception but the occasional foot-stomp of a stubborn lawmaker.

J.D. Tuccille is managing editor of 24/7 News at Reason.com.