He publicly pledged at the time that none of them would be punished, to which one student replied thusly:

“That is only a slogan by him, it’s not true,” he said. “Whoever criticises him will have a hard time. They don’t do anything now, but rather they wait for a month or so, or even the next year, and when we want to enroll at university they won’t let us…”

Bingo. Not only are they out, but the university chancellor came bearing notices of eligibility for military service. Which is precisely what Ahmadinejad “joked” would happen while they were heckling him. The Guardian, December 18:

Witnesses say Mr Ahmadinejad also tried to ridicule the students by referring to the university disciplinary code, under which those with three penalty points are suspended from studies. “He joked that he was going to issue a presidential order for those with three stars to be enlisted as sergeants in the army. That made the students really angry,” said Mr Zamanian.

The lesson: when he tells you he’s going to do something, believe him.

Go read the Telegraph article linked at the top about the pride student dissidents take in having penalty points, or “stars,” assessed against them. Quote: “The star system has, however, become a badge of honour among those who have acquired them on their records. Students have likened it to the German Nazi-era practice of making Jews wear the Star of David, a comparison that acquired new relevance last week when Ahmadinejad aroused international disgust by hosting a conference in Teheran for people who deny the Holocaust.”