Edward Snowden noted former CIA agent, whistle blower and advocate for user data security shared his opinion about 2 of the cryptocurrencies and said how they're different from others.
He in reply to one of tweets of a twitter user said that it's because of secure transactions and anonymity of the ZCash that it's different from other currencies and said that it's one of the most interesting Bitcoin alternative. He added
"Bitcoin is great, but if it's not private, it's not safe".
(Source twitter)
He also gave his opinion when asked about Monero that it's a great project but pointed out it's weaknesses like how a bug detected in it and also because being an amateur crypto it has a great consequences for people like him.
https://www.coindesk.com/monero-link-transactions-debate/
(Source twitter)
He said all this about Monero referring to a link in which there's findings that transactions of Monero can be linked meaning that these are not secure
(All the content is taken from twitter)