China: Protesters and Police SMS each other

After SMS and email messages were used to organize crowds that resulted in anit-Japan marches and riots in Shanghai and other cities, the Chinese police are fighting back by sending warning SMS to everyone.
But will that have any effect on the marchers who have been communicating for weeks under the governments's radar?
Is this an example of a Smart Mob or just a mob and an attempt at mob control?
See the full article in today's NYTimes.