It would be foolish not to save what you’ve created. Currently only available for Mac, Tumblr has rolled out a beta of a program that will do just that. Tumblr Backup can be downloaded from Tumblr.com/downloads/tumblrbackup-mac-beta.zip. As of press time, this program could not be used to back up private posts, notes, submissions from other people, auto-feed posts or audio files. You also have to run the backups manually, for now. But, better safe than sorry.