February 2, 2011, 4:34 p.m.

When Michael Oren, the Israeli ambassador to the United States, was invited to UC Irvine last February to speak on the subject of U.S.-Israeli relations, members of the Muslim Student Union, a campus group, decided to protest his presence. They did so by repeatedly disrupting his speech — about a dozen times, standing up one by one to shout anti-Israel slogans until each was removed from the room.

The behavior of the students was wrong. They could have held up signs or distributed leaflets or chanted slogans outside the lecture hall, but they should not have tried to shut down the event by making it impossible for Oren to speak. Protesters have the right to voice their objections in many ways, but not to silence those they disagree with. This principle is especially important at a university, which exists, in part, to promote the free exchange of ideas.

The students were removed from the hall by police. Eleven were arrested and cited for “disturbing a public event,” although they were not criminally charged at the time. After an investigation, which found that the Muslim Student Union had planned the protest and subsequently conspired to deny its involvement, university officials suspended the group for an academic quarter.

Get the best in Southern California opinion journalism delivered to your inbox with our Opinion L.A. newsletter. Sign up »

That seemed reasonable. There was some dispute over whether it was the group that should have been punished or the individuals involved, but discipline of some sort was in order. The suspension ended last month; the group remains on probation.

Now, however, as the anniversary of the Feb. 8 fracas approaches, the Orange County district attorney’s office is apparently considering bringing criminal charges against the students before the deadline to do so expires. A grand jury in Orange County has been hearing testimony.

Criminal charges, however, are not appropriate. They would be overkill, a punishment out of proportion to the offense. Is it really necessary to threaten the futures of students who engaged in a nonviolent protest that didn’t, ultimately, stop Oren from delivering his remarks? These students have been punished already, in an effort to make clear the difference between legitimate protest and their unacceptable actions. We hope they’ve learned a lesson. Now it’s time to move on.