The popular phrase “where there’s smoke there’s fire” is a lie. Lots of things cause smoke without fire. Smoke bombs, for example. And barbecue, which is so integral to a happy life that no reasonable person could imagine the world without it. Anyone who claims that fire always accompanies smoke is a barbecue denier. I refuse on principle to even have a conversation with someone like that.

And yet, we live in a society that, for very good reasons, often acts like smoke and fire always go together. For example, in the last ten years, I have, on three different occasions, been evacuated from a hotel room well past midnight because a smoke alarm went off. Each time, I and a few hundred of my new best friends were roused from bed by a loud and pervasive alarm. We trudged down the stairs, most of us in bare feet, and waited for someone to tell us to go back in. Once it was even snowing.

Each time I evacuated, I was pretty sure that it was a false alarm--somebody set it off with a cigarette, maybe, or the chef burned something in the oven. I have even known smoke alarms to be set off by the steam from a hot shower. Lots of smoke; no fire.

But each time a smoke alarm rings I dutifully evacuate, even though I know it is probably nothing. One reason for this is that a hotel alarm is  so piercing that I would walk across hot coals to get it to stop. Another, though, is that I perform a simple calculation in my brain that goes something like this: there is probably a 1% chance that this is a fire and a 99% percent that it is nothing. However, if I act like it is a fire when it is not a fire, I will be out a few minutes of time and some cold feet. But if I act like it is not a fire when it is a fire, I will be dead, which is more than 100 times worse.

The evolutionary medical researcher Randolph Nesse refers to this calculation—which has been hard wired into our brains over millions of years of natural selection—as the “smoke detector principle.” The smoke detector principle is diametrically opposed to another principle, famous in song and story, known as “the boy who cried wolf.”

According to the BWCW principle, you shouldn’t raise false alarms because this will make you less likely to be believed when the alarm is true. But this is a reading that goes against the facts in the story. The men who didn’t listen to the boy the third time lost all of their sheep to a real wolf. Clearly, they should have risked the minimal expenditure of running to the scene one more time. This is Cost-Benefit 101.

This is all a very long preface to what I really want to talk about, which is the persistent rumor that President-elect Trump is currently discussing plans for registering all Muslims in the United States. Yesterday, the Reuters news service reported that the idea of a Muslim registry was raised by Kris Kobach, a member of Trump’s transition team. The Trump camp denied it the same day. But then, in an interview with Fox news’s Megyn Kelly, a Trump surrogate used the example of the Japanese Internment Camps in World War II as precedent for a national registry of Muslims that would presumably (like the camps) include American Citizens.

When I forwarded the Reuters article onto my Facebook feed yesterday, along with my very strong sentiment that a Muslim registry would not be acceptable in the United States, several people called me an “alarmist” and suggested that I (like Reuters) was “crying wolf.” People told me that this was only about a watch list of recent immigrants from certain high-risk countries. George Bush did the same thing. The Supreme Court would never allow such a thing to happen because we live in an advanced industrial democracy and not a banana republic. All of this is probably true within a reasonable margin of certainty. I was, as one good friend said, “freaking out about nothing.”

I will happily admit that I am an alarmist . But I reject the notion that I am freaking out about nothing. Rather, I am freaking out about almost nothing—a fairly small possibility that the things being discussed in the presidential transition could become a full-scale registry of American citizens and legal immigrants based on their religious beliefs. This would be plainly unconstitutional--a clear violation of both the 14^th Amendment and the founding principles of our republic. It would also be a concession to dictatorship. We cannot go there.

And, as many people have pointed out, it is probably not going to happen. But "probably" is not good enough (remember back last week when Hillary Clinton was probably going to be president?) The chances that it will happen are are well above zero. For one thing, the current president-elect said during the campaign that he would do precisely such a thing. I guarantee you that, had President Obama actually ever promised that he would take away everybody’s guns, people would have believed him. And we are now having a full-scale national discussion about such a registry based on things that a prominent politician and member of a presidential transition team said to a reporter. This may not be a fire. But it is definitely more smoke than I want in my hotel room.

Anybody who genuinely worries about things like liberty, equal treatment under the law, and religious freedom would do well to freak out about even the minute possibility of a religious-based registry for citizens and legal immigrants. Yes, there are safeguards to keep such things from happening. But, as we learned with Executive Order 9066 and Korematsu v. United States, the safeguards are not foolproof. Alarms are necessary because we cannot accept even a chance of something like this happening again. We need to keep the lines bright and clear to make sure that nobody crosses them when we aren’t looking. That’s what freaking out is for, after all. And that is what smoke alarms are supposed to do.