The official explanation for Stephen Downs’ arrest last week at a shopping mall in Albany, N.Y., is that he was being disruptive.

You have to push Tim Kelley, an executive of the company that manages Crossgates Mall, to get him to define “disruptive.” But eventually he says it means Downs was “engaging in or trying to engage other shoppers in conversation.” Which sounds about as disruptive as an afternoon nap.

But prod Kelley some more, and he will admit that the arrest was also prompted by the T-shirt Downs was wearing.

So what was on this shirt? Did it show a swastika? A single finger salute? A naked lady holding a swastika while giving a single finger salute?

Nope. Downs’ T-shirt, which he had custom made in the mall, carried only two slogans expressing his opinion of the pending war with Iraq. On the back: Give Peace A Chance. On the front: Peace on Earth.

That’s it. Downs says he didn’t hand out any leaflets or chant any slogans. He just put on his new shirt and went down to the food court for dinner. He says he had only two “conversations.” One was with a teen-ager who admired the shirt and wanted to know where he could buy one like it. The other was with a law school student who struck up a dialogue with Downs, a 60-year-old attorney. They chatted about some courses the student was taking.

At which point, Downs says, security guards approached and gave him an ultimatum. Take off the T-shirt or get out of the mall. When Downs refused, the guards went away, only to return with police officers. They repeated the demand, he repeated his refusal and Downs was arrested for trespassing.

This is not, technically speaking, a First Amendment issue. Our right of free speech prevents the government from telling us what we can and cannot say, but as private entities, neither Crossgates nor any other mall is legally required to tolerate an opinion it does not like.

Of course, you only have to visit your favorite store to know how infrequently the average merchant seeks to censor. Americans, after all, are famous for expressed opinions. We use our caps, our bumpers, our T-shirts to proclaim everything from our favorite ball team to our preferred political candidate to our position on abortion, gun control and reparations. And yet most days, we are still allowed to buy our baloney and bagels.

Self-expression is part of who we are. In some ways, the best part. So it’s hard to imagine being turned away from your local supermarket because the manager disagrees with you about the death penalty. Or at least, it was until last week.

Stephen Downs won’t need a legal defense fund, though. The mall has declined to press its flimsy charges. Kelley wants you to know it’s safe to wear a T-shirt expressing your opinion while shopping at Crossgates. Surely you’re as grateful for his generosity as I am.

I suspect Kelley has come to realize that, while the mall may have the law on its side, it has nothing else. Indeed, there’s something chilling in the very fact of Downs’ arrest. Especially in light of local media reports that this isn’t the first time Crossgates has ejected shoppers wearing anti-war slogans.

But maybe it’s the last. After word of Downs’ experience circulated, 150 protesters showed up at the mall wearing T-shirts like his. One hopes mall management got the message: this is the United States of America, still. And it means something.

What a strange pass we have come to. Here on war’s eve, people are saying all sorts of things you never thought you’d hear. Some say we must strike a nation that has not struck us. Others say we ought to use torture to extract information from prisoners. And still others say nuclear weapons are no longer out of the question.

How ironic, in light of all those strange and unsettling opinions, that a shopping mall would decide it is Stephen Downs who has said the one thing that ought not be said.

Peace.