London police mulled shutting down the Twitter microblogging service at the height of the rioting but had no power to do so, the city's top police officer said. Scotland Yard officials, including Metropolitan Police Service Acting Commissioner Tim Godwin, discussed shutting down the social-networking Web site "a few times" as rumors about further rioting spread, Godwin told the House of Commons Home Affairs Select Committee Tuesday. After learning police had no legal power to shut it down, Godwin raised the subject with the government, which led to discussions that are continuing about changing the law, he said. "I contemplated seeking the authority to switch it off," The Daily Telegraph quoted Godwin as saying. "The legality of that is very questionable. We did not request that it was turned off, but it is something we are pursuing as part of our investigative strategy." Police said much of the disorder during five nights of widespread rioting, protesting, looting and arson in London was orchestrated on sites such as Twitter. BlackBerry Messenger was also used by youths planning riots, police said. The instant text messaging system cannot easily be monitored by police, but police were able to monitor some messages by seizing smartphones from people arrested on suspicion of conspiring to commit public order offenses, Godwin testified. Conservative Member of Parliament Louise Mensch called last week for sites such as Twitter and Facebook to be shut down during riots. "If in a major national emergency police think Twitter and FB should take an hour off, so be it," she said. "I don't have a problem with a brief temporary shutdown of social media, just as I don't have a problem with a brief road or rail closure," she said. "If short, necessary and only used in an emergency, so what? We'd all survive if Twitter shut down for a short while during major riots."