You might want to read up on what an NSL actually is, since you and the GP are clearly very confused.

Explain, please.

What prevents an NSL from compelling Google from minting a new certificate (they are a CA), providing the keys to the bad guys, and distributing that certificate in Chrome? NSLs have been used in the past to compel positive action (c.f. Lavabit), so I really don't see how you think there's any practical limit to their power.

My understanding is that there isn't a limit. If I am wrong about this, then kindly reply directly here so we can all learn instead of giving the "read up on" non-answer.

An NSL can be used only to compel release of connection or transaction metadata, and cannot be used to compel disclosure of message contents. It's basically a fast-track for getting things like call records, and it most emphatically cannot be used to compel turning over a certificate or allowing a man-in-the-middle.

To my knowledge the exact details of the Lavabit case were never released, but from what has been released it's quite clear that the issue was regarding a warrant and a gag order, because the ensuing litigation wouldn't have been remotely applicable to an NSL (otherwise Lavabit's attorney would have won on a walk).

None of this is to say that I think NSLs should exist. In fact, I think they're a terrible idea. But the vast majority of discussions around them and similar topics is so grossly uninformed that it's impossible to take most people seriously on these subjects.

Okay, so not an NSL. Incorrect terminology pointing at the same awful effect, an unaccountable court issuing unchallengeable rulings that cannot be discussed.

No substantial difference from the concept I'm complaining about.

"Ignorance more frequently begets confidence than does knowledge."

It's a letter, issued by an occult kangaroo court, that coup d'etat forces hold in hand while demanding the keys to the kingdom - a demand that can't be challenged in a legitimate court of law.