When it comes to covering the debate over modernization of the 1978 Foreign Surveillance Act, usually professional members of the media often expose their deep ignorance on the issue. This Sunday on Meet the Press, Tim Russert asked CIA Director Gen. Michael Hayden

MR. RUSSERT: After September 11th, the NSA began to eavesdrop, wiretap Americans without court approval. That has now stopped, you need approval by the FISA courts, Foreign Intelligence Surveillance Administrative courts. How many Americans were eavesdropped on after September 11th?

GEN. HAYDEN: I can’t get into, into the specific numbers, but I can tell you that every aspect of that program has now been briefed to every member of the House and Senate Intelligence Committee and the House and Senate Judiciary Committees. And, and to make sure everyone understands precisely what we’re talking about here because, again, this kind of casual use of language–you didn’t use it, and I appreciate it–but, but a lot of folks have called it “domestic spying, domestic eavesdropping.” In every case these were international calls.

MR. RUSSERT: Was it hundreds or thousands?

GEN. HAYDEN: No, I, I, I won’t get into the numbers, Tim. But I think if I, if I were able to, I, I, I’d think the numbers would, would cause you less alarm.

Gen. Hayden can not get into the details of the program because it is classified. But piecing together what we do know from the public record, his characterization of the program as “eavesdropping” on “hundreds or thousands” of Americans was grossly misreading. Heritage Foundation senior legal policy analyst Andrew Grossman explains:

Opponents of modernization have dragged out debate on what should be a no-brainer with wild-eyed “Big Brother” scenarios. They have poisoned the debate by using misleading terms such as “warrantless wiretapping” and raising a stink over proposals to give immunity to communications providers that cooperated with the government’s electronic surveillance program.

Under FISA and other laws, domestic wiretapping — that is, listening in on phone calls — requires a warrant or order from a judge. Modernization doesn’t change that. Modernization is really about electronic surveillance — looking at the e-mails, instant messages and other Internet activities of terrorists outside of the U.S.

The problem is that, unlike with wiretapping, there’s no way to capture all of the Internet traffic of just one individual or group. A terrorist cell might keep e-mails on one server, run a Web message board on another and store bomb-making manuals on a third. These could be in different countries, and they could be accessed from anywhere in the world.

Because of the way the Internet works, many of these communications, even if they begin and end outside the country, still pass through the U.S. And all that traffic passes through the same pipe as everyone else’s Internet communications. So the only way to get at foreign terrorists’ communications is to tap the entire stream of traffic.

The often-ignored next step — and the crucial one for Americans’ privacy and the effectiveness of intelligence operations — is “minimization.” This is the process of filtering the stream of traffic to remove domestic communications and communications that don’t have any intelligence value.

Minimization is imperfect — on the Internet, it’s hard to tell where a communication originates or winds up — but it’s the only way to get the job done, given the quantity of Internet traffic. And it protects privacy: Sophisticated algorithms can do a good job of automatically filtering out domestic communications.

The main issue in modernization is whether FISA, created to oversee domestic surveillance, should apply to this kind of surveillance of foreign communications, many of which just happen to pass through the U.S.