Responding to suggestions that Facebook and similar businesses might be required to vet conversations on their sites on behalf of the government, Amnesty International UK Legal advisor, Rachel Logan, said:

“The UK government must not turn companies like Facebook into snoops.

"The murder of Lee Rigby was an abhorrent crime and of course governments should and must provide the police and security services with the resources they need to stop violent crime.

"The notion that social networking sites should be made responsible for detecting plots would reduce trust in both the government and the businesses themselves.

“If the government starts treating businesses like an arm of the security services, where will it end? Today it might be Facebook - tomorrow it could be your local pub, newsagent or coffee shop that is required to spy on its customers.

“Public safety is paramount, but not at the cost of turning the UK into a surveillance state.”