Benjamin Wittes plays his appointed role as "liberal who agrees with conservatives about all the topics he writes about" (it seems shocking that Jeffrey Rosen wasn't available) and defends the new wiretapping law:

To know whether the new law represents a strong long-term policy response to the technological changes now challenging FISA, I would have to know a lot more about the NSA's surveillance technologies both in the 1970s and now than is public. I would want to know also how the NSA interprets phrases like "reasonably believed to be located outside of the United States" and how it means to handle situations in which such people turn out, notwithstanding the agency's reasonable belief, to be running around Cleveland.

But for whatever it's worth, had I been a Democrat on Capitol Hill, I would not have opposed this change as a six-month interim step while I studied such questions. And I would not have felt that I had sold out, surrendered, or caved in by giving the intelligence community what it says it needs while giving myself the time to decide if I agreed.

I may not be a Fellow and Research Director in Public Law at The Brookings Institution or a member of the Hoover Institution Task Force on National Security and Law, but here's a wild guess as to how the NSA is going to interpret the phrase "reasonably believed to be located outside of the United States" -- they'll interpret it so as to give themselves as broad a mandate as possible. Other ambiguous phrases, likewise, will be interpreted so as to give themselves as broad a mandate as possible. What's going to happen when they mess up: as little as possible. This is why, in the real world, we look not at administrative guidelines but rather at enforcement mechanisms.

Rules and interpretations of this sort aren't self-enforcing (you can look it up in Wittgenstein) which is why the significant part was way up higher in the piece:

"Hang on," I hear you cry. "Wasn't the 1978 FISA a restraint on government surveillance power? Didn't it put a court between the spooks and their targets? And doesn't this law remove that court in vast numbers of cases?" Yes to all.

And there's the rub. Absent meaningful checks and balances -- or even the prospect of embarrassing public disclosure -- the rule can say anything you like. It could be "surveillance is allowed only for really good and worthy purposes, and never for bad and abusive ones" and it wouldn't make any difference.