Orange County District Attorney Tony Rackauckas said he filed the criminal case Friday because the incident at the University of California at Irvine was an "organized (attempt) to squelch the speaker," the Los Angeles Times reported.
The university suspended the Muslim Student Union, which denied planning to block the speech, in a rare sanction against a student group for reasons other than hazing or alcohol abuse. Individual students were also disciplined.
When he spoke at UC Irvine Feb. 8, 2010, Ambassador Michael Oren was shouted down repeatedly until police ejected the hecklers.
The district attorney accuses the students of planning their action with other Muslim Student Union members in person and by e-mail in advance.
The defendants are charged with misdemeanors of conspiracy to disturb a meeting and disturbance of the meeting. If convicted, they could be fined and get probation or six months in jail.
They are to be arraigned March 11.