The arrest of artist Mark Chase for painting at Baltimore'sInner Harbor without a city permit for engaging in commercial activity there raises an interesting First Amendment and civil liberties issue: When is making a painting in a public place a constitutionally protected act of expression, and when is it just a shtick to make a few bucks? In Mr. Chase's case, the answer seems to be a little of both.

Mr. Chase was arrested Sunday by Baltimore police after he set up his painting gear outside Harbor Place and refused to leave when told he was violating trespass laws. It's not altogether clear whether the artist actually intended to sell his paintings to passersby or whether he was merely inviting them to tip him for the pleasure of watching his works take shape.

In either case, he appears to have been relying on a temporary ruling issued by a federal district court this month barring Ocean City officials from enforcing restrictions against artists who perform on the streets. Mr. Chase had sued the city for violating the artists' First Amendment rights by requiring them to obtain permits and by prohibiting them from selling their work in certain areas. The court's order remains in effect as long as litigation in the case continues.

Nevertheless, the Ocean City ruling does not automatically give Mr. Chase the right to paint in Baltimore without a permit, though he could certainly argue that a similar principle is at stake. On the other hand, the city has a legitimate interest in protecting theInner Harbor's value as a tourist destination by making sure vendors don't engage in offensive, disruptive or dangerous activities that create a public nuisance.

Like many cities, Baltimore requires buskers — people who dance, sing, play music or perform on the streets in exchange for donations — to audition for a permit. That prerequisite is based on the not unreasonable theory that maintaining a certain level of quality among the acts is necessary to attract visitors, or at least not to turn them off.

And despite Mr. Chase's objection to such restrictions on First Amendment grounds, it's still far from clear how the courts ultimately will rule on the merits of his complaint. The temporary stay against Ocean City allows street artists there to sell work without a permit if what they produce can be considered "expressive material," but that's a far cry from a blanket ban on any and all types of restrictions.

Mr. Chase clearly has an entrepreneurial spirit and a gift for grabbing the media spotlight in ways that advance his artistic ambitions. In his case, the artworks and the act of creating them — together with the constitutional and public policy issues they raise — are so thoroughly intertwined that all three become part of his creative performance.

The proof of that lies in the final twist of this bizarre incident, when James Perry Cyphers, who had accompanied Mr. Chase to the harbor in order to record his performance, was prevented by police from videotaping the artist's arrest, even though it occurred in public place. That was a clear violation of Mr. Cyphers' rights, for which the police department, which obviously needs to bone up on the Constitution it is sworn to protect, should apologize. Given that the department is currently being sued by the ACLU for one of its officers' actions in stopping an observer from videotaping an arrest at the Preakness, it should be a little more sensitive to this issue.

Still, it would be a pity to see Baltimore drawn into protracted and expensive litigation over the city's clumsy handling of Mr. Chase, which did nothing to help the image of the harbor the restrictions on buskers were intended to protect, and in fact probably had just the opposite effect. The city could make more productive use of its efforts if it were to wrap up negotiations with the ACLU in another lawsuit about restrictions on First Amendment expression at theInner Harbor — currently confusing patchwork of rules based on what areas are considered private and what areas public.

As for Mr. Chase himself, he's already made his point, and it has been duly noted. If what's important to him is his freedom of expression as an the artist — or just the media attention and potential financial benefits from his new celebrity — he's already won this round.