The Islamic conservative part of the government used their resources to move several hundred thousand Basij militiamen and other supporters to the capital for a demonstration. The object of this operation was supposed to be Israel, but in fact it was Iranian moderates. The conservatives don't want to come right out and say to their armed supporters, especially the largely rural Basij, that these "liberal city kids" are bad Moslems and maybe something should be done. No, that might start the civil war everyone, so far, wants to avoid. Fewer Basij showed up than the government expected.
But the Basij keep themselves busy as guardians of the public morals. In an average week, Basij nation wide will arrest over a thousand people for "immoral behavior." This can range from drinking beer to getting caught in a brothel. Every week, Basij zealots will seize 500 satellite TV dishes. Watching foreign TV is forbidden. The Basij also patrol the borders looking for drug smugglers, arresting 100-150 a week. By their own count, the Basij stop and admonish (and sometimes slap around) 30,000 people for "unIslamic behavior." The Basij are not very popular with most Iranians. But the Basij have guns, beards and a "we're on a mission from God" attitude that is very intimidating.