Richard at the Peking Duck has pointed to a post noting that a white-collar worker in Shanghai has been sentenced to five-years for sending out material via cellphone (short message service, SMS) ahead of the anti-Japanese demonstration:

A 25 year old white collar worker, Tang Ye (汤晔), made a summary of information already available on the internet about the anti-Japanese demonstrations, including route, time, other relevant facts, and broadcasted this summary through his cellphone, resulting in his arrest under "disruption of social order" charges.
According to information from Chinese media sources in early May, this text message "resulted in serious consequences". Tong ye was sentenced to jail for five years. For a young white collar worker, five years time does not mean five years. It could throw Tong off course for the rest of his life. And all because of a cellphone text message. China’s "Big Brothers" came down hard on Tong as a show of authority, to bring text messages under their sphere of influence.

I posted on this a few weeks back. The main difference between the account noted by Richard and the one I had earlier noted was that in the account I had read he was arrested for an e-mail message. I don’t have any further details but that still seems more likely than being arrested for an SMS. E-mails are more easy to trace and would contain more detailed information on which to base charges (if that actually mattered).

ESWN has some more details here.