A year has passed since the American former intelligence contractor Edward J. Snowden began revealing the massive scope of Internet surveillance by the U.S. National Security Agency.

His disclosures have elicited public outrage and sharp rebukes from close U.S. allies like Germany, upending rosy assumptions about how free and secure the Internet and telecommunications networks really are.

Single-handedly Snowden has changed how people regard their phones, tablets and laptops, and sparked a public debate about the protection of personal data.