Nope. Maybe it used to be true, but not as of 2007.

"…prohibits you…from disclosing this letter, other than to…an attorney to obtain legal advice or legal assistance with respect to this letter.""

Source: http://upload.wikimedia.org/wikipedia/commons/9/91/EFF-IA_Na...

Is it interpreted as singular, "an attorney", or can you send NSLs to everyone in the American Bar Association for a second opinion?

It's good to shop around, especially here in California, one of the states where graduates from non-accredited law schools can join the bar. :-)

I can't see a reasonable way of establishing bona fides other than creating a strong implication/inference of "national security".

(My wife is a federal attorney, and it is disappointing how warped "the government's" perspectives are on rights and what is reasonable.)

Just saying, there is no law on god's earth that would stop me talking to my girlfriend. The government simply does not have that right and I would NEVER recognise it.

You don't have to recognize that right so long as you're willing to take Snowden's route: flee to a country that is willing to stand up to the US and never return.

The law doesn't work by individual consent, it works by hitting individuals with sticks or locking them in closets until they comply.