Pop quiz: Where does the boldfaced language in the excerpt below come from? Con law junkies will know, but anyone who’s been reading this site for the past two weeks should have a hunch.

The Metropolitan Transportation Authority approved new guidelines for advertisements on Thursday, prohibiting those that it “reasonably foresees would imminently incite or provoke violence or other immediate breach of the peace.”

The 8-to-0 vote by the authority’s board came three days after pro-Israel ads characterizing Islamist opponents of the Jewish state as being “savage” began appearing in subway stations, setting off vandalism, denunciations of the authority and calls for the ads’ removal…

“We’ve gotten to a point where we needed to take action today,” Joseph J. Lhota, the authority’s chairman, said at a news conference on Thursday.

Give up? Re-read this post for the answer. It’s the “fighting words” exception to the First Amendment, the trojan horse by which anti-blasphemy laws and other fun “sensitivity” regulations will eventually be smuggled into American law. Here’s how the Supreme Court described the standard for “fighting words” when it first announced the doctrine in 1942:

Allowing the broadest scope to the language and purpose of the Fourteenth Amendment, it is well understood that the right of free speech is not absolute at all times and under all circumstances. There are certain well defined and narrowly limited classes of speech, the prevention and punishment of which have never been thought to raise any Constitutional problem. These include the lewd and obscene, the profane, the libelous, and the insulting or “fighting” words — those which, by their very utterance, inflict injury or tend to incite an immediate breach of the peace. It has been well observed that such utterances are no essential part of any exposition of ideas, and are of such slight social value as a step to truth that any benefit that may be derived from them is clearly outweighed by the social interest in order and morality.

The “fighting words” exception, as I’ve said before, amounts to a heckler’s veto to your freedom of speech. It’s pernicious in two ways. One: It makes your First Amendment rights contingent upon the sensitivities of others. If the object of your criticism is prone to responding violently, then it’s incumbent upon you to shut up and not offend them. A “right” that disappears when someone gets especially angry about your exercise of it ain’t much of a right. Two: In practice, it operates as moral sanction by the state for vigilantism. The point of the “fighting words” doctrine is to let the cops step in and arrest an offensive speaker before any violence goes down; it’s essentially a form of appeasement to the insulted party, signaling that they don’t have to do anything crazy because the state will punish their enemy for them. (Seems familiar.) Needless to say, the incentive this creates for an offended audience to resort to, or at least threaten, violence is high. Between Mona Eltahawy spray-painting a pro-Israel ad that she didn’t like and the MTA responding the way they have today, you’re seeing a nifty example of “fighting words” logic in action. Obviously this isn’t a criminal case, just a new state policy on which subway ads they’ll run, but the dynamics are the same. Some people saw the ads and couldn’t control themselves, and therefore it’s the ads that must be silenced. Grotesque.

But wait, you say — isn’t this actually the Brandenburg v. Ohio standard at work, not the “fighting words” exception? Nope. That was the point of the post that I asked you to re-read. The Brandenburg case is supposed to cover situations where the speaker is trying to rile up a mob that’s on his side. There’s no heckler’s veto at work; on the contrary, the speaker in a Brandenburg scenario is trying to use the mob to silence his enemies by intimidating them. Note the Supreme Court’s language in the original opinion:

These later decisions have fashioned the principle that the constitutional guarantees of free speech and free press do not permit a State to forbid or proscribe advocacy of the use of force or of law violation except where such advocacy is directed to inciting or producing imminent lawless action and is likely to incite or produce such action.

“Advocacy,” not insults. Brandenburg has nothing to do with offending an audience and everything to do with, say, an Islamist demagogue telling a roiling mob of fanatics that it’s time to go burn down the local U.S. embassy. In fact, offhand, I can’t imagine a fact pattern where a fixed ad like the “Support Israel, Defeat Jihad” posters in the NYC subway system could meet the Brandenburg test for incitement. Even an ad that’s overtly violent, e.g., “Burn down the Supreme Court,” isn’t “likely” to result in anyone taking “imminent” action. The whole point of Brandenburg is to give speakers a wide berth in using incendiary language, with the state permitted to step in only at the last minute if some sort of riot or violence is already brewing. Whereas the whole point of “fighting words” is to limit a speaker’s ability to use incendiary language by letting his political enemies dictate what he is and isn’t allowed to say. If anything, the legal paradigm should be reversed: Force the guy who’s riling up a mob to be circumspect with his language and force the audience that’s prone to violent reaction to be extra tolerant of people with whom they disagree. Instead, we have the system we have. The sooner the Supremes change it, the better.