Edward Snowden is a well-known whistleblower who leaked NSA documents to the media in 2013.
Snowden wrote on his Twitter account that Zcash privacy makes it the best alternative to Bitcoin. When asked about Monero Snowden replayed that it is an amateur crypto and may be traceable by government agencies, and therefore is not anonymous.he added that Monero also had some issues with bugs at the beginning of the year.
Monero and Zcash are both altcoins that focus heavily on privacy. Monero uses ring signatures and stealth addresses while Zcash uses its operation called zk-snarks.