An ambiguous public statement, of course, can serve as a dog-whistle to your supporters while giving you plausible deniability. Ambiguous orders are even more useful: they put all of the details of what the orders actually mean in the hands of ground-level enforcers.

This has several important benefits for autocrats:

When rules are explicit, people can obey them. When rules are vague but penalties are harsh, people censor themselves: they keep far away from anything which might violate the rules.

When rules are explicit, they can be used as defenses. If deporting someone requires a court finding that they are in the country illegally, for example, then there are suddenly lawyers involved, there is a burden of proof to be met, and the process is slow and deliberate, in much the way you would expect a legal process which is capable of taking away someone’s home, work, family, and country all at once would be. If, on the other hand, ICE can raid businesses and round people up by the hundreds if they can’t prove their legal right to work on the spot (can you?), or if CBP can detain people at the border more or less arbitrarily (something we’ll get to below), it’s a lot harder to figure out who you have to convince to let you go, and how you might do that. Personal relationships with people in power become much more useful than procedural guards.

And, of course, ambiguous orders can be “changed” in ambiguous ways that don’t really matter — much as the Muslim Ban order first included permanent residents, then didn’t, and (as the 9th Circuit wisely recognized) there’s nothing whatsoever to prevent them from changing it again later.

A more direct version of this shows up in an essay of mine from late 2015, talking about the logistics of Trump’s plan to deport 11 million people in two years. The hard first step of such a plan is figuring out who you want to deport; but as I noted there,

Identifying people is harder than it sounds, since it’s not like everyone has proof of citizenship tattooed on their arms. You’ll have to put people in the field, and they’ll have to have a lot of leeway to deal with ambiguous cases. Which is another way of saying they need the power to decree someone an outsider and deport them.

I am sad to say that this essay seems more relevant with each passing month.

To reiterate an important point, none of this is saying that Trump is an evil genius, or that this is a carefully orchestrated plan — everything in this piece is simply about Trump doing exactly what he said he would.

With this in mind, let’s look at some ways things could go wrong.

But first, a cute dog. Isn’t he sweet?

Threat Model #1: I’ve Got A Little List

Last week, Hina Shamsi, the director of the ACLU’s National Security Project, and a US permanent resident, was flying back from the Dominican Republic when she was taken aside by border patrol and questioned extensively about her activities and what she was doing outside the country. Why would someone working for an organization with “American” in its name not be a US Citizen? Why would someone whose job supposedly has to do with the Constitution be traveling so much outside the country?

The extensive questioning while not free to leave and without counsel is hardly unusual; CBP has long had essentially unlimited powers at the border. What’s important about this story is that the CBP agents immediately recognized her as an ACLU lawyer.

That’s the biggest part of this story. For this to have happened at all, the CBP needed to have a list of potential “anti-American” actors which flagged Shamsi’s name, as well as enough details about those individuals to support an interrogation on the spot. And it’s very clear that no amount of power is likely to protect you from such a list; Shamsi literally represents a building full of angry lawyers, and if you are willing to poke at that, there isn’t much that wouldn’t make sense to poke.

A second story this week was that Secretary of Homeland Security John Kelly told Congress that he would like to demand passwords from all visa applicants. In parallel, the government has subpoenaed Facebook for access to the accounts of people rounded up in D.C. during Inauguration Day protests. Police already can, and do, demand these — and citizens at the border are no exception, as US-born NASA scientist Sidd Bikkanavar found a few days ago.

To understand how these two items are related, ask yourself what information you get from accessing someone’s social media accounts, or by getting the passwords to their phone or accounts.

You get people’s private messages and photos. If you do this by demanding someone’s password (and suggesting that they will be deported, their visa revoked, etc., if they don’t comply), then you can do this without having to go through Facebook’s, Google’s, Apple’s, Snapchat’s, or Twitter’s lawyers — another set of buildings full of angry lawyers that you don’t necessarily want to poke. Done this way, you also get SMS messages, Signal messages, and so on, all straight from the phone.

You get people’s complete social graph: their contacts (on the phone plus on all the various social services). That’s especially juicy if the person is a journalist or a lawyer (“hey, look, here are this person’s sources / clients!”).

The first thing lets you find out what people have been talking about. This is useful in the context of ambiguous orders — like when Canadian citizen Fadwa Alaoui was turned back at the border (after a password search) because they “found videos on [her] phone which are against us.” The videos in question were simply Muslim prayers, but CBP has effectively unreviewable discretion — and now her DHS record includes that she has been “previously denied access to the United States,” a major red mark.

The second thing lets you connect people: do you follow subversives? Say, people who are organizing demonstrations? How about ACLU lawyers? Relationships can be used to both incriminate you and others.

This is one of those points where it’s particularly important to remember what ambiguity means. If you’ve written something down in social media, you might have thought about whether it’s defensible in court (i.e., if it’s legal) or whether it’s defensible in public (i.e., if it’s moral). But you probably haven’t asked yourself if it’s defensible when you’re being interrogated by a border patrol agent at the end of a flight, in a secluded room where you have no access to your family or lawyers, and yet no right to leave.

If you grew up under an authoritarian regime, you’ll of course recognize this last category: it’s “defensible to the secret police,” which is a very different bar indeed.

As a technical note: If you’re wondering how much information they could get from having your password for a few minutes, standard forensic software lets you plug in a phone and basically suck down the entire contents of everything on it, plus signed-in accounts from a variety of common apps, quite quickly. Half an hour should give them everything for most users.

If we put all of this together, here’s meaningful threat model #1: Dissidence, or knowing dissidents, or expressing support for them, is now enough to get you on a List. These lists are in the hands of Border Patrol, and likely soon a range of other police and police-like agencies, and are being used as the basis for interrogations. If you aren’t a US Citizen, this can easily mean deportation, even if you’re under a green card.

Watch for more reports of people being detained at the border, or by police for reasons like “being too close to a demonstration,” and facing consequences due to their political or religious speech. You might also keep an eye out for propaganda describing various kinds of opposition groups as being anti-American or terrorist organizations — antifascist groups being a likely first target.

A symbol of Jewish Antifascists — triple parentheses and the “Iron Front” triple arrows. Getting caught with this in your social media could get you branded a terrorist supporter.

Support for a terrorist organization is, of course, a serious crime, and simply having reference to such things on your phone is very good reason for the police to arrest and/or deport you. At least, so they assure us.