The American cloud storage and file synchronization company Dropbox Inc. had several security and privacy controversies. Issues include a June 2011 authentication problem that let accounts be accessed for several hours without passwords; a July 2011 privacy policy update with language suggesting Dropbox had ownership of users' data; concerns about Dropbox employee access to users' information; July 2012 email spam with reoccurrence in February 2013; leaked government documents in June 2013 with information that Dropbox was being considered for inclusion in the National Security Agency's PRISM surveillance program; a July 2014 comment from NSA whistleblower Edward Snowden criticizing Dropbox's encryption; the leak of 68 million account passwords on the Internet in August 2016; and a January 2017 accidental data restoration incident where years-old supposedly deleted files reappeared in users' accounts.