He revealed this while on a remote interview of the New Yorker Festival, where he was asked a couple of variants on the question of what we can do to protect our privacy.
He said that on an individual level, people should seek out encrypted tools and stop using services that are “hostile to privacy.”
For one thing, he said you should “get rid of Dropbox,” because it doesn’t support encryption, and you should consider alternatives like SpiderOak.
He also suggested that while Facebook and Google have improved their security, they remain “dangerous services” that people should avoid. (Somewhat amusingly, anyone watching the interview via Google Hangout or YouTube saw a Google logo above Snowden’s face as he said this.)
His final piece of advice on this front: Don’t send unencrypted text messages, but instead use services like RedPhone and Silent Circle.