This image was lost some time after publication.

In representing the New York Police Department, which is facing charges that officers improperly detained hundreds protestors during the 2004 Republican convention, the New York City Law Department has subpoenaed MIT doctoral candidate Tad Hirsch, creator of TxtMob, demanding he turn over the time, content, and identity of people who sent and received SMS messages through the service. Hirsch says most of the data is gone, and his lawyer argues the subpoena is overly broad.

Text messages have become a favorite tool of direct action organizers worldwide, because they make it easy to quickly disseminate information to large groups and can be read and written even while sirens wail or helicopters make low passes. The NYPD was aware of the service at least a month before the convention, according to secret internal documents revealed last year by the court. Why not just ask the NSA to turn over their archives from the event? That seems easier. (Photo AP/Mary Altaffer)