A group of hackers has threatened to publish the personal data of Research in Motion employees if the Blackberry maker co-operates with police investigating UK riots by handing over user data.
As a warning, the hacker group - calling itself Team Poison - defaced the official Blackberry blog and posted a message threatening further retaliation, according to the BBC.
Earlier in the week, Research in Motion (RIM) said it would co-operate with the police after it was revealed London rioters used Blackberry Messenger, rather than Twitter, to organise looting sprees across the capital.
Blackberry Messenger (BBM) is free to use, private and encrypted, so messages appear to be difficult for the police to intercept. "We have engaged with the authorities to assist in any way we can," said Blackberry UK.
Team Poison said it did not condone innocent people or small businesses being attacked in the riots, but said it supported attacks on police and government.
The hacker group said it was opposed to Blackberry giving user information to police because it could lead to the wrong people being targeted.
"Innocent members of the public who were at the wrong place at the wrong time and owned a Blackberry will get charged for no reason at all," the group said.
Team Poison said it would release Blackberry employee information, including names, addresses and phone numbers if the company went ahead with plans to help police.
The UK's Regulation of Investigatory Powers Act (RIPA), does however, enable police to request data from mobile phones when that data relates to criminal activity.