On Sunday the Tel Aviv police arrested Natali Cohen Vaxberg, a radical artist and left-wing activist who published a video clip on the Web that shows her defecating on an Israeli flag while the national anthem, “Hatikva,” plays in the background. The district police chief, Maj. Gen. Benzi Sau, rushed to inform the press of her arrest and declared the 20-second clip “extremely crass.” Yesterday, a court fined Cohen Vaxberg, released her to house arrest and forbade her to surf the ‘Net for the next month.

The person who spurred the police to action was the radical right-wing activist Yoav Eliasi, better known as “The Shadow.” A few months ago, after viewing another installation by the same artist, Eliasi commented, “I’d like to say she ought to be stoned to death, or at least executed in the public square, but I won’t say it. What I will say is that she should be stripped of her citizenship immediately.” The police hastened to appease The Shadow and his buddies on the right, and a spokeswoman for the Tel Aviv police said, “The Israel Police respects freedom of expression, but it isn’t an absolute value. ... This was a severe and extreme act that damaged the symbols of the state and the public’s feelings.”

The law allows someone who “injures the honor of the state flag or the honor of the state emblem” to be fined and sentenced to up to a year in jail. But this law has rarely been enforced, and it’s hard to figure out what public interest is served by persecuting a marginal artist who posted a 20-second video clip on the Web. The police didn’t take such energetic action when Bratslav Hasidim posted a clip on the Web that showed an Israeli flag being burned last Independence Day.

In the United States, Supreme Court rulings have held that burning the national flag falls under the rubric of freedom of expression. In Israel, indictments have been filed against dozens of ultra-Orthodox Jews, Arabs and left-wing activists who burned flags, but in almost every case the courts have refrained from convicting them, preferring to uphold freedom of expression.

Defecating on the flag assuredly hurts the feelings of many Israelis and expresses a demonstrative lack of patriotism on the artist’s part. One could also question the video’s aesthetic value. But freedom of expression exists precisely to protect acts such as this. Cohen Vaxberg wasn’t trying to disturb the peace or encourage violence, only to be provocative.

The police’s job is to fight crime and maintain domestic security, not to act as the radical right’s agent for silencing people it dislikes.