A problem for data scientists

If flash mobs or riots (like the ones in London) are organized using Twitter, Facebook, BlackBerry and SMS, won't it be very easy to catch the people responsible? Not only are the organizers / initiators easy to track down, but with geolocation (GPS or cell tower) and a court order it would be easy to determine whether any particular individual had participated. Perhaps current privacy laws prevent that data from being stored, but we can easily modify the laws if necessary.

Where are those law enforcement data scientists when you need them? :-)