Ever since former NSA contractor Edward Snowden disclosed the US surveillance program PRISM, which collects and analyzes information from Internet and phone users around the world, people have been shocked at the extent to which the American government has been spying on them for years.

US President Barack Obama is due to unveil his plans to reform the NSA - will they go far enough to curb the spy agency's powers and to appease European allies? DW takes an in-depth look at the data surveillance scandal.