The Federal Bureau of Investigation (FBI) has said it is concerned that privacy protections being brought in by Silicon Valley will make it easier for criminals to hide from the law.
Tech companies are increasingly taking steps to limit its ability to access customer data, with Apple recently claiming that it would no longer be possible to bypass passwords on iPhones and iPads.
James Comey, director of the FBI, said: "I am a huge believer in the rule of law, but I am also a believer that no-one in this country is beyond the law.
"What concerns me about this is companies marketing something expressly to allow people to place themselves above the law."
Advanced security technology also is able to restrict encryption key access to the owners of a given piece of data, eliminating the risk that governments will approach a firm to take information without the owner’s knowledge.
The proliferation of this technology poses a problem for spooks and police, who in some countries have built extensive data collection capacities, as revealed by the leaks from NSA contractor Edward Snowden.
"There will come a day – well it comes every day in this business – when it will matter a great, great deal to the lives of people of all kinds that we be able to with judicial authorization gain access to a kidnapper’s or a terrorist or a criminal’s device," said Comey.
"I just want to make sure we have a good conversation in this country before that day comes."
