A media watchdog says who want to identify rioters in London and other cities through their smartphones.
Reporters Without Borders said Blackberry has already provided Scotland Yard with information about a number of Blackberry users.
British rioters and looters were able to organize rapidly through Blackberry's encrypted text messages. The nights of rioting were sparked by a police shooting last Saturday in Tottenham.
Reporters Without Borders says it is not minimizing the "gravity of the situation" in the United Kingdom, but the group says it believes providing personal data to the police sets a "disturbing precedent" in a western country and could have "significant consequences" for setting an example for other kinds of government.
The media watchdog group said it was "shocked" by suggestions from several politicians that Blackberry should suspend its messaging service. The group urged British authorities "to rule out any possibility of shutting down or drastically restricting the use of social networks."
Reporters Without Borders also voiced concern about British Prime Minister David Cameron's suggestion that television broadcasters have a duty to hand over unused footage of the rioting to the police. The group said doing so would turn the television broadcasters into "police auxiliaries and seriously endanger their independence."
Some information for this report was provided by AP, AFP and Reuters.