The Secure Empty Trash feature in Finder in Apple OS X before 10.11 improperly deletes Trash files, which might allow local users to obtain sensitive information by reading storage media, as demonstrated by reading a flash drive.
https://support.apple.com/HT205267
http://www.securitytracker.com/id/1033703
http://lists.apple.com/archives/security-announce/2015/Sep/msg00008.html