Privacy takes the front stage in transientBug. That being said, don't store truly sensitive information on transientBug.
All user data is stored on transientBug servers, and the official web extensions only communicate with the transientBug API over an HTTPS connection.
The following data is sent by the official web extension when its page action is clicked: The active tabs Title and URL. That's it.
transientBug does backup its database to aid in the recovery of the service should the worst happen. These backups are stored in a secured, private Digital Ocean Space and are retained for up to a week.
Backups will not be used to recover deleted accounts or bookmarks.
If you request your account to be closed, all your bookmarks, authorized apps, and developer apps are destroyed. Gone forever. In the event that the service is restored from a backup, accounts which were recently closed but were recovered during a database restoration will be deleted again after the restore is complete.