The American Civil Liberties Union on Wednesday sued the Washington Metropolitan Area Transit Authority, the government agency that operates the capital region's subway system and its primary bus network. The ACLU argues that the transit agency's policies for accepting advertisements on its subway stations, trains, and buses violate the First Amendment by discriminating against controversial and non-mainstream viewpoints.

The plaintiffs in the lawsuit are ideologically diverse: the ACLU itself, an abortion provider, People for the Ethical Treatment of Animals, and alt-right-Internet-troll-to-the-point-Twitter-actually-banned-him Milo Yiannopoulos.

The inclusion of a self-described "alt-right" figure like Yiannopoulos helps to demonstrate the ACLU's point that WMATA's policy squelches free-speech rights across the political spectrum. But Yiannopoulos' inclusion has also raised the hackles of some on the political left, who see associating with the controversial author as beyond the pale. Chase Strangio, an ACLU attorney who has represented whistleblower Chelsea Manning, posted a statement calling Yiannopoulos "vile" and attacking the ACLU for defending his First Amendment rights.

But the ACLU has a long history of defending the First Amendment rights of groups far outside the mainstream, including Nazis and the Ku Klux Klan. As such, the organization hasn't backed down from its defense of Yiannopoulos. "Protecting the First Amendment rights of all of these speakers is crucial to the ability of civil rights movements to make the change we need to make," the group argued in a Wednesday blog post.

Vague and discriminatory

The controversy began in 2015, when anti-Muslim activist Pam Geller tried to place ads depicting a cartoon of the prophet Muhammad on DC subways. That put WMATA in a difficult position, because some Muslim extremists have threatened violence against anyone who publishes Muhammad cartoons.

In an apparent effort to duck the controversy, WMATA announced that it was suspending "issue oriented" advertising across the board.

Of course, the big problem here is that it's not so clear what counts as an "issue oriented" ad. For example, military contractors have long taken out lavish ads touting their latest fighter planes. Are they merely advertising commercial products or are they trying to influence policy decisions about what hardware to buy?

The ACLU believes that the "no issue ads" standard is unworkable and unconstitutional, and it assembled a group of plaintiffs to illustrate the point:

The ACLU itself sought to place ads displaying the text of the First Amendment, in English, along with translations into Spanish and Arabic. These ads were rejected because WMATA "does not take any issue oriented advertising."

The abortion provider Carafem submitted an ad to promote an FDA-approved abortion pill "for Abortion Up to 10 Weeks. $450. Fast. Private." WMATA rejected the ad, and even the agency selling the ad space on WMATA's behalf was surprised. "Quite honestly, we do not see why this was not approved, your ad doesn’t appear to be in violation of any of the guidelines," the agency wrote. WMATA told Carafem that "because your ad addresses the controversial topic of abortion and promotes a particular abortion product, it is issue-oriented."

Milo Yiannopoulos is a writer who has grown famous by baiting liberals on issues like race and gender. He was uninvited from the conservative CPAC conference after video surfaced of him defending pedophilia, and he has been banned from Twitter for repeatedly encouraging followers to harass women and minorities like Ghostbusters star Leslie Jones. When he published a book earlier this year, WMATA initially accepted ads for the book—ads that didn't themselves make any controversial statement about issues. But after a public outcry, WMATA backtracked and removed the ads. WMATA refused to explain to Yiannopoulos why it removed the ads.

WMATA rejected ads from People for the Ethical Treatment of Animals that would have read "I’m ME, Not MEAT. See the Individual. Go Vegan." WMATA rejected the ads as impermissible issue ads. As the ACLU notes, WMATA has accepted ads that promote "eating animal-based foods, wearing clothing made from animals, and attending circus performances at which animals are made to perform in unnatural ways."

A couple of things are obvious from this list. First, while Yiannopoulos' participation in the lawsuit has gotten the most attention, the ACLU isn't only defending the rights of right-wing provocateurs like Yiannopoulos and Geller. Groups defending left-wing causes like animal rights and abortion rights have also been affected.

Second, while WMATA might have thought "issue ads" were a clear and value-neutral category, in practice it has turned out to be unworkably vague. Rules that allow companies to hawk fighter jets and hamburgers, but ban anti-war and animal rights groups from advertising, is the opposite of viewpoint-neutral. The WMATA's guidelines give the agency unfettered discretion to decide which positions are too controversial to appear in ads, and that seems hard to square with the First Amendment.

Hate speech and free speech

The ACLU is generally viewed as a liberal group, but its absolutist stance on the First Amendment doesn't fit well with everyone on the political left. A growing contingent of left-wing thinkers have come to see "hate speech" as a serious problem and free speech absolutism as an obstacle to addressing it.

Controversy has become more common over the last eight months as the ACLU has attracted a wave of new supporters alarmed by the Trump presidency. Many people donated to the ACLU in the expectation that the group would oppose Trump administration policies—and the group has done plenty of that. But not all of the ACLU's new donors understood the depths of the ACLU's commitment to free speech rights.

"Especially for many of our new members, they may be surprised by the ACLU's robust First Amendment positions," ACLU staff attorney Lee Rowland said in February. "But it's certainly not new."

Over time, defending the free speech rights of right-wing extremists has become something of a trademark for the group. For example, in 2012 the ACLU sued the state of Georgia defending the right of the KKK to "adopt a highway" in the state. In 2010, the group defended the free speech rights of Fred Phelps, the infamous pastor who pickets the funerals of LGBT soldiers with anti-gay messages.

The ACLU has been doing this kind of thing for almost 100 years now, and it's not likely to stop any time soon. Individuals who don't want their donations supporting the rights of people who engage in "hate speech" might be wise to research organizations ahead of time.