The revelations by the former NSA operative, Edward Snowden (now to be charged with espionage himself), about the massive extent of state snooping on telephone calls and internet traffic, shocked even the most sanguine. The authorities, however, on both sides of the Atlantic, came out with the same stock response verging on justification: if you are innocent you have nothing to worry about.

The quite disgraceful conduct of police undercover agents described by another whistleblower, Peter Francis, gives the lie to this complacent and arrogant mantra. The perfectly innocent family of Stephen Lawrence was targeted in an attempt to discredit and undermine its quest for truth. Not for the first time has the state tried to depict victims and their families as disreputable and unworthy of belief: Bloody Sunday, Jean Charles de Menezes and Hillsborough are other recent examples.

With the Met, if you are innocent you have everything to worry about | Michael Mansfield World news: Surveillance |