The only domestic "mass surveillance" program in Snowden's dumps was phone metadata collection, which everyone did know about since 2006. https://usatoday30.usatoday.com/news/washington/2006-05-10-n...
The sensational parts of Greenwald's reporting were not supported by Snowden's documents or any other documents. Anybody who parrots those claims will rightfully be called a tinfoil hatter.