I always criticise Dr Ledeen when he overestimates or exaggerates, so it's only fair to point out reputable sources that say he has understated the crackdown on students (though this is a first).

Ledeen: ... the actual number could be upwards of 6-7,000.

Asharq Al-Awsat: Over the past two weeks, more than 8,000 students have been arrested during demonstrations against the regime and religious clerics. (plus the inevitable Khatami I-will-resign threat).