What did the Edward snowden hack that made him a criminal of america but a hero to the world?

Edward Snowden, the whistleblower,  a hero, a dissident, a traitor, and a patriot. Whatever name it may be but the work he has done is still a debatable issue and still in discussion.

According to the wiki, He is an American computer professional, former Central Intelligence Agency (CIA) employee, and former contractor for the United States government who copied and leaked classified information from the National Security Agency (NSA) in 2013 without authorization. His disclosures revealed numerous global surveillance programs, many run by the NSA and the Five Eyes Intelligence Alliance with the cooperation of telecommunication companies and European governments.

Basically know for