BlackBerry maker RIM has faced calls from a British member of parliament to have its messaging service shut down to prevent rioters from communicating.
After yesterday's riots, David Lammy, a Labour MP for Tottenham, has called on RIM to shut down the BBM instant messaging service.
"Immediate action needed," Lammy said over Twitter.
"[Londoners] cannot have another evening like last night tonight. BBM clearly helping rioters outfox police. Suspend it."
Yesterday, RIM said it would "assist" authorities battling the riots, amid reports that the BlackBerry Messenger (BBM) service was being used to organise looting.
Meanwhile, hackers managed to post a message on BlackBerry's official British blog, warning RIM against blocking the service.
The message told RIM that if it shared data with the police, "you will regret it", claiming to have access to RIM's employee database and threatening to pass it on to rioters.
A spokeswoman for RIM said the company was working on a statement to be issued soon. The message has since been removed from the blog.
It remained unclear whether BBM was actually of any significance to the riots, and how easily RIM could shut down the service.
Kathryn Wynn, a lawyer for Pinsent Masons, said RIM and any other firm could legally hand data to the police.
"Neither RIPA (re interception of emails) nor the Data Protection Act (disclosure of emails and user names to the police) will stand in the way of RIM co-operating with the police because the interception or disclosure is for the purposes of the prevention or detection of crime," Wynn said in a blog post.
"However, from a data protection laws perspective, RIM will need to ensure that the disclosure is proportional for the purposes.
"Therefore, if possible and in the light of the urgency of the situation, the company should avoid disclosing the messages or details of obviously innocent users.
"RIM should also ensure that any disclosures are made using secure media."
Separately, eBay has issued a statement saying it would remove any listings that clearly feature items stolen during the riots.
“Our thoughts are with the businesses and communities affected by recent events in London and around the UK," the company said in a statement to The Next Web.
"eBay will cooperate fully with the investigating authorities to identify and remove any listings which are linked to criminal activity.”