By now, you may have already seen Vice News’s extraordinary documentary “The Islamic State.” (As of this writing, it’s been viewed on YouTube more than 3 million times and counting since mid-August.) Vice boasts that “reporter Medyan Dairieh spent three weeks embedded with the Islamic State, gaining unprecedented access to the group in Iraq and Syria as the first and only journalist to document its inner workings.” Dairieh’s access is indeed unprecedented, and the product is gripping. He is shown traveling with ISIS fighters, interviewing Muslims who migrated to the caliphate, speaking with prisoners in an ISIS jail who proclaim their repentance and gratitude to the caliphate, and bouncing around the Syrian city of Raqqa in the jeep of the new “morals police” (hisba), who are also, in the video at least, met with the profuse gratitude of the locals. It is a journalistic score that would make any ambitious reporter or news organization envious, and a feat now almost impossible for Western journalists after the executions of James Foley and Steven Sotloff.

It could also be construed as a federal crime if the U.S. government wanted to prosecute Vice or Dairieh.

The law that the documentary may violate is a prohibition on providing material support to designated foreign terrorist organizations (FTOs), or even just “terrorists.” Of course, the U.S. wants to block the flow of money, materiel, and men to groups like ISIS or, say, the ultra-Zionist Kach movement, which, like ISIS, is among the 59 groups on the State Department’s FTO list. (Incidentally, this is also the law that prevented the families of Foley and Sotloff from paying ransoms.) But the government’s definition of material support goes beyond, well, material, and encompasses “service, including currency or monetary instruments or financial securities, financial services, lodging, training, [and] expert advice or assistance.”

At first glance, there is nothing troubling about this at all. The U.S. wants to block people from giving money to terrorist groups, and so it wants to criminalize the act of advising them on how to hide, launder, or move money. The government also wants to destabilize those groups and prevent them from controlling territory, so it might reasonably want to stop someone from advising them on how to organize a police force, operate a consumer-protection office, or grow food in the desert more productively.

But the government’s conception of what it means to deprive terrorist groups of assistance toward their goals goes beyond that. In essence, outlawing “material support” extends to the objective of isolating any terrorist group from any kind of cooperation with the outside world, and this goes for all groups on the State Department’s FTO list, from al-Qaeda to the Kach group, the Basque “Fatherland and Liberty” (ETA) organization and the Kurdistan Workers’ Party (PKK). In the test case that came before the Supreme Court in 2010, Holder v. Humanitarian Law Project, the Court held that it was constitutional to prohibit a group of humanitarian legal professionals (including a retired U.S. judge) “from engaging in certain specified activities, including training PKK members to use international law to resolve disputes peacefully; teaching PKK members to petition the United Nations and other representative bodies for relief; and engaging in political advocacy on behalf of Kurds living in Turkey and Tamils living in Sri Lanka.” The Court rejected the claim that the statute “should be interpreted to require proof that a defendant intended to further a foreign terrorist organization’s illegal activities.” Instead it affirmed that the statute prohibits “‘knowingly’ providing material support” and that Congress was within its rights to choose “knowledge about the organization’s connection to terrorism, not specific intent to further its terrorist activities, as the necessary mental state for a violation.” In short, according to the Court: expert advice + coordination with a terrorist group = federal crime.

That decision means, for example, that Jimmy Carter and his Carter Center could be in violation of federal law for giving peacemaking advice to groups on the State Department’s FTO list. Any private individual who coordinates with a group on that list, or a group that the individual ought to know engages in terrorism, with the purposes of providing it advice or assistance—even on how to pursue an end to its campaign of violence—is guilty of a crime by the logic of the Roberts Court. In the justices’ judgment, the government’s interest in delegitimizing and weakening any such group easily outweighs constitutional rights to speech and association.

What about journalists like Dairieh and media outlets like Vice? They evidently coordinated with ISIS—Vice proudly advertises Dairieh’s three-week embed with ISIS fighters. But is providing a group with an outlet for its views a kind of service? This question was the subject of another important case, perhaps the most consequential material-support case since Humanitarian Law Project: Tarek Mehanna v. United States.

In that high-profile 2011 trial, the government successfully prosecuted Tarek Mehanna, a Muslim man from the Boston area, on material support-related charges that were largely based on two sets of activities: a one-week trip he took to Yemen, purportedly in search of a jihadist training camp with the hope of moving on to Iraq, and his translation and dissemination of texts and videos favorable to jihadist viewpoints and activities. (Mehanna was convicted on all charges and sentenced in April 2012 to 17 and a half years in prison.) While the government did attempt to prove that Mehanna engaged in these translations in coordination with al-Qaeda or al-Qaeda in Iraq, the evidence that he actually did so falls far short of the coordination with ISIS that Vice explicitly announces in its marketing for Dairieh’s documentary.

More importantly, while the government spent most of its time during the Mehanna trial attempting to document his state of mind in discussing, translating, and disseminating Islamic religious material related to jihad, none of that material was aimed at actually coordinating or directing a terrorist attack. None was what’s known as “crime-facilitating speech,” like instructions on how to build a bomb, forge a passport, or sneak into a battle zone. It was all speech related to explaining, defending, and disseminating a certain point of view (one that, incidentally, at times dissented from al-Qaeda’s party line). But, as the lead prosecutor informed the jury, “One way to provide material support is providing yourself as personnel. Another way to provide material support is to provide your friends as personnel, or people who might read the translations, might read the propaganda that you put out on the Internet that you want to go fight” (my emphasis).

Note that in order to be considered as having provided material support to terrorists, you don’t need to know the people who might be inspired by translations or propaganda. Anyone who consumes it could be your gift to a terrorist group.

So what? If the law targets terrorist propaganda outlets and recruiters who set out to help such causes, isn’t it a reasonable restriction on free-speech rights?

Remember from the Supreme Court decision that you don’t even need to desire or specifically intend to further a terrorist group’s violent or illegal aims (although most of Mehanna’s trial did focus on the desire, since there was so little evidence of coordination). Your aim could be to spread peace, human rights—or public knowledge through journalism. There is nothing in the state of the law as it stands now that prevents the government from charging Vice with a federal crime for coordinating with ISIS and providing the group with an outlet to show a different side of its caliphate than that seen in the Western media and beheading videos. Who, after seeing the Vice documentary, did not come away with a slightly more nuanced view of the group? (Now imagine you are a young, idealistic, Salafi-inclined Western Muslim.)

As it happens, the Supreme Court has a chance to take another look at the material-support statute and walk back its own jurisprudence, at least as it pertains to speech. The Court met on Monday for its so-called “Long Conference” to decide which cases to take. Among them is the Mehanna case.

Assuming it takes the case, the Court could do a number of things. It could draw a very tight line around what counts as explicit coordination with a terrorist group on the Internet (although this would not help Vice or other news organizations in direct contact with terrorists). More importantly, it could draw a brighter line between speech delivered as advice on technical matters and speech that merely contributes to the circulation of radical, violent, and hostile ideas.

It is unlikely (although hardly unimaginable) that Vice will be prosecuted for making its ISIS documentary. But the example highlights how anti-terrorism laws are quickly heading in the direction of criminalizing behavior that is hard to imagine as criminal: Jimmy Carter’s peace missions, documentaries, newspaper op-eds, and even academic research or publishing. America has faced, and is facing, bigger challenges than jihadist ideology. It’s possible to fight terrorism without shutting down all pro-jihadist speech. But it’s not possible to fight it without understanding it, or confronting ideas with ideas.