Home Secretary Theresa May joined David Cameron in thanking social networking site Friends Reunited for shutting down following the widespread disturbances in English cities earlier this month.
The move follows a meeting between senior ministers, the police and representatives of Facebook, Twitter and Blackberry on Thursday.
"Despite not being at the meeting, Friends Reunited appears to have taken the lead in shutting down its website" said Home Office minister Lee Wilson. "This sends a clear message to potential troublemakers that they will not be able to plan their criminal acts in advance using this particular site."
A spokesman for Friends Reunited commented "Wait. What? Shutting down? We haven't shut down. There's someone online right now."
"Hang on, that's me."