"How Toy Story 2 Nearly Vanished" or "TEST your backups, people!"
Here's a link to a video short created by Pixar on how they lost almost all of Toy Story 2 and didn't have a good backup.
I always recommend customers test their changes and plans for changes on a TEST environment before implementing anything in production (this is especially true for ANY change in permissions). Most of us rest comfortably at night knowing that somewhere, there is a team of reliable people responsible for database backups and that they can be called upon to restore your data should you need it restored.
TRUST BUT VERIFY
But, have you ever tried to actually have that team restore last night's database backup as a test? Can they actually restore the data to a location of your choosing where you can walk through your documented recovery steps? Oh, wait! You do have documented recovery steps, right? You have tested and understood those, too, right? When I was responsible for production data on a Project Server, I tested data restores from the backup media itself once every three weeks. I restored the data to a test server and provisioned PWA against that server with those databases. Because of this, I could reassure managment (and keep my job) that if the worst did happen, I could restore the data with a high degree of confidence. I know I slept better because of that.
Please work with your backup team closely so you know how often the backups take place, where they go, and that they can be recovered. Once you know the data can be recovered, please test restoring it to a test environment to make sure you know how to do it and please document those steps. The documentation is critical because you may be on vacation the next time there's a hard drive failure that wipes out your data and the poor guy or gal who has to do the recovery may have no idea how to proceed.