Here's my situation: Say you run a service online that stores information that users of the service would want to keep for a long time. This information could be notes, files, etc. but it is information that the user should be able to trust will be there when they come back.
What patterns, method, techniques, etc. exist that could be put in place on the website/service to ensure that even the administrator would be unable to delete any of this data (with malicious intent, not by accident which could be fixed through backups or using rollback in a database). Something that reassures to the users that their data couldn't even be deleted by the guy running the service essentially securing the user of the service from attacks of availability from the administration.
My current thought is that since, for all intents and purposes, this administrator has root privileges to everything there is nothing that could be done to prevent the information being deleted from the service. One potential idea I had would to allow the user the option to export the data locally so that they could keep copies of their data.
I tried searching for something like this but I guess not a lot of people are thinking about this from the user's point of view.