Widespread encryption and stopping bulk collection of communications data will cripple intelligence agencies, says a former top UK spy.

“Everything can’t be private or we’ll end up regretting it,” said Sir David Omand, director of the UK’s signals intelligence agency GCHQ from 1996-97, speaking at University College London January 15.

“Very serious damage” will be done to the ability to carry out foreign espionage and police domestically if “you have the right to have your private iChat and nobody has the right to intercept it,” Omand, now a visiting professor of war studies at King’s College London, added.