The New York Civil Liberties Union’s claim that police searches at subway stations are intrusive did not find a favorable audience yesterday.

The three-judge panel that heard the case at the 2nd Circuit Court of Appeals asked a series of questions suggesting that it did not find the random stops at subway entrances that began last year particularly burdensome to passengers.

The police program of checking the bags of random passengers at certain stations began in July 2005, following the deadly bombing of the transit system in London. In New York, subway passengers are free to decline to have their bags inspected and may leave the station without further police contact. A lawyer for the NYCLU, Christopher Dunn, said he believed that more than 1 million people entering the subways have been searched, which he claims is a violation of constitutional rights.

One of the judges, Jon Newman, asked: “How much intrusion is there when some person, without adverse consequences, can resist? Isn’t it so that it has never happened to someone who doesn’t want it to happen?”

Judge Charles Brieant pointed out that a passenger was free to leave one station and take a train from a different station.

Judge Chester Straub was also on the panel. The panel did not issue an opinion yesterday.

Following a non-jury trial six months ago, a federal judge upheld the program. The city submitted information on how it carried out the searches, but those papers are sealed.

An attorney for the city, Scott Shorr, said the city did not use the stops to search for ordinary contraband. In the first three months of the program, police officers did not find drugs, guns, or cans of spray paint, he said yesterday.

Mr. Shorr argued that the subway searches are not necessarily unconstitutional just because they are unprecedented. He compared the discomfort some passengers felt at the searches to how people felt when airports first instituted searches about 30 years ago.

“We are seeing that terrorist attacks do something to diminish our expectation of privacy,” Mr. Shorr said.

Even if the program never resulted in police discovering a bomb, Mr. Shorr said, the prospect of searches could disrupt the plans of terrorists who were considering the subway system as a target.

When weighing whether a police program is constitutional, Mr. Shorr said, part of the standard should be if the proposed program “looks effective” in preventing terrorism.

This last argument did not sit entirely well with the court. “If your argument is correct, would that not justify suspicion-less searches at a busy intersection like Times Square?” Judge Newman asked.

In his rebuttal, Mr. Dunn said there was no difference between police searches at subway entrances and police searches on street corners.

“I submit to you there is no difference in the legal principle that applies to this and the legal principle that applies to stopping people on the sidewalk,” he said.