The letter comes as countries in Europe have moved over the past year to regulate or mandate legalized access for criminal and national security investigations.
SAN FRANCISCO, CA – JUNE 02: Attendees gather at the Apple Worldwide Developers Conference at the Moscone West center on June 2, 2014 in San Francisco, California. Apple CEO Tim Cook kicked off the annual WWDC which is typically a showcase for upcoming updates to Apple hardware and software. The conference runs through June 6. (Photo by Justin Sullivan/Getty Images)