A few minutes into the police encounter that ended with his arrest for disorderly conduct, Henry Louis Gates Jr. reportedly exclaimed, "This is what happens to black men in America!" It would be more accurate to say this is what can happen to anyone who makes the mistake of annoying a cop.

Whether or not race played a role in the incident, Cambridge police Sgt. James Crowley clearly abused his authority, retaliating against the Harvard professor for his disrespect by hauling him away in handcuffs. The highly publicized arrest illustrates the threat posed by vague laws that give too much discretion to police officers who conflate their own personal dignity with public safety.

Crowley, responding to a report of a possible burglary in progress from a woman who saw Gates forcing open a jammed door to his house, quickly realized he was not dealing with a break-in. Gates explained that he lived in the house, which he leases from Harvard, and supplied a university ID confirming that he was a member of the faculty. Gates says he became angry because Crowley nevertheless continued to question him.

Even if we accept Crowley's version of events, the arrest was not justified (a conclusion reinforced by the city's decision to drop the charge). Let's say Gates did initially refuse to show his ID—an understandable response from an innocent man confronted by police in his own home. Let's say he immediately accused Crowley of racism and behaved in a "loud and tumultuous" fashion. So what? By Crowley's own account, he arrested Gates for dissing him. That's not a crime, or at least it shouldn't be.

In Massachusetts, as in many states, the definition of disorderly conduct is drawn from the American Law Institute's Model Penal Code. A person is considered disorderly if he "engages in fighting or threatening, violent or tumultuous behavior...with purpose to cause public inconvenience, annoyance or alarm" or "recklessly creates a risk thereof."

Crowley claims Gates recklessly created public alarm by haranguing him from the porch of his house, attracting a small crowd that included "at least seven unidentified passers-by" as well as several police officers. Yet it was Crowley who suggested that Gates follow him outside, thereby setting him up for the disorderly conduct charge.

It's hard to escape the conclusion that Crowley was angered and embarrassed by Gates' "outburst" and therefore sought to create a pretext for arresting him. "When he has the uniform on," a friend later told The New York Times, "Jim has an expectation of deference."

As the Massachusetts Appeals Court has noted, "the theory behind criminalizing disorderly conduct rests on the tendency of the actor's conduct to provoke violence in others." Yet police officers often seem to think the purpose of such laws is to punish people for talking back to cops.

"You don't get paid to be publicly abused," Michael J. Palladino, president of New York City's Detectives Endowment Association, told the Times last week. "There are laws that protect against that." A Brooklyn police officer agreed, saying, "I wouldn't back down if there's a crowd gathering. If there's a group and they're throwing out slurs and stuff, you have to handle it."

In this context, the relevance of the gathering crowd is not the potential for a riot but the potential for losing face. A policy of zero tolerance for public slights may be appropriate for a gangster, but it's not appropriate for a peace officer charged with enforcing the law.

Among other things, the law guarantees the right of citizens to criticize public officials. Sometimes the criticism is justified. In fact, the more outrageous police conduct is, the more likely it is to provoke an angry response that can be cited as the basis for a disorderly conduct arrest.

When a police officer faces unfair criticism, the best response may be to walk away. Sometimes swallowing your pride takes more courage than standing your ground.

Jacob Sullum is a senior editor at Reason and a nationally syndicated columnist.

© Copyright 2009 by Creators Syndicate Inc.