Usually at the beginning of a zero-tolerance campaign, those leading the charge promise it will vanquish the worst of the worst: the drug kingpins, the gang leaders, the serial sexual predators, the murderers. But it inevitably turns out there aren’t very many of them. So the definition of what will not be tolerated starts expanding, allowing politicians and other moral arbiters to say they are cleansing society of those who commit any kind of lapse. People who urge a more proportionate, incremental and individualized response to complex problems are tarred as being some percentage — usually 100 — tolerant of the menaces that trouble us.

A central example of this kind of category expansion is the sex-offender registry. It began more than 20 years ago after several horrific murders of children by serial predators. Today, around 900,000 people are on the registry. Exceedingly few of them are the kinds of criminals who prompted the list in the first place.

One is an 18-year-old in New Hampshire who asked a 15-year-old of his acquaintance for sex. Nothing happened. But adults found out about the proposition, and because the 18-year-old made the request via computer, he is on the registry for life.

Then there is the severely intellectually disabled Missouri man who was being molested by a younger male neighbor. The neighbor then convinced the man, who was then 26 years old and living with his parents, to expose himself to an underage female. Both the men were arrested, and the disabled man has been on the registry ever since. Because of his conviction, he can no longer participate in the Special Olympics or clear tables at a local restaurant where he used to work. The legal bills exhausted his parents’ retirement funds.

Despite the overwhelming evidence that zero-tolerance policies sweep up the harmless and the innocent, we are so habituated to thinking in zero-tolerance terms that when a new issue appears, it is often our default response. Some feminists, myself included, have raised this concern about this aspect of the #MeToo movement. We worry that a zero-tolerance approach could undermine the movement’s moral authority by destroying the careers of men without first fairly assessing the allegations against them and by failing to make distinctions about a wide range of misconduct.

Zero tolerance is also washing over corporations in the form of firings for speech that is deemed offensive. You can agree that Roseanne Barr deserved to be fired for her overtly racist tweet about Valerie Jarrett and also be concerned that people are losing their jobs for far less.