The often-maligned American Civil Liberties Union took a laudable step this week in Boise where it conducted a training session to explain the rights of individuals who are stopped for questioning or detained by authorities.

The specific audience for which the class was intended was Muslims, who are being subjected to increasing interrogation by FBI officials, according to Marty Durand, an attorney with the Idaho ACLU.

The pattern is not disputed by the FBI. A spokesman in Salt Lake City said the agency’s 56 field offices around the nation are initiating increased contacts with Muslim, Sikh and Arab American leaders. Special Agent Bob Wright, quoted in a story in Sunday’s Spokesman-Review, said talking to members of those ethnic communities enables agents to find out about “unusual situations or activities that might be classified as suspicious or out of the ordinary, or something that would be indicative of violations of law.”

The idea of singling out members of minority groups for special attention by law-enforcement agencies provokes an instinctive discomfort. Still, given what happened on Sept. 11, 2001, and is continuing to happen in the Middle East, it is hard to imagine a reaction to Islamic terrorism that doesn’t focus attention on Islamic populations.

The worry is that such an investigation, being done in the name of protecting American security, might become overzealous and result in abuse of the rights of those people, citizens and noncitizens, who don’t fit the traditional image of what an American looks like. Or, as Durand put it:

“The people we’ve spoken with want to be cooperative and try to be cooperative, but after, you know, your third or fourth round of questioning, some people are wondering what their rights are, what kinds of questions they have to answer.”

Special Agent Wright, meanwhile, said that part of the FBI’s purpose is to uncover evidence of hate crimes and other activities that may victimize members of the Islamic population. Remembering that the internment of Japanese and Japanese Americans during World War II was defended in part as necessary for their own protection, such a rationale needs to be taken with caution.

Nevertheless, Durand and other ACLU representatives made it clear they were not attempting to undermine legitimate law-enforcement efforts, just to make sure that people who might not understand their rights gain a better idea of when they are obliged to answer questions and when they are entitled to decline.

(An English-language version of the ACLU pamphlet “Know Your Rights” is available online at www.aclu.org/kyr/kyr_english.pdf.)

American freedom needs to be defended on many fronts. In this case, the American Civil Liberties Union is living up to its name.