To keep the site clear of information that is no longer being accessed, we sweep abandoned accounts periodically. Accounts that don't have a verified email address within 2 days, accounts that have no profile photo within 5 days, and accounts that have no activity for 90 days are all swept from the system. You can find more information on that here.
We do a database backup weekly, Saturday at 2am. This doesn't affect the users and is simply us saving your data to keep it safe for you if a server goes down or something cataclysmic happens. We keep active backups on the server and an off-site storage system in order to keep your data as safe as we can.
Interactions are swept after they are more than 6 months old. Since the interaction system was an add-on, it has some special quirks, and must be cleaned periodically. Please don't do full roleplays in the interaction inboxes, as you will lose data after 6 months.
"Likes" more than a year old are swept. The first time, we accidentally removed pages and groups from this, causing people to need to rejoin those pages/groups they had joined or liked more than a year prior. In future sweepings, we will set it to ignore those databases, so this won't happen again. All other likes will be swept once they're a year old, as with all of the likes on posts, comments, and blogs, that database spirals out of control pretty fast.
Mail messages cannot be fully deleted by the users here. It's one of the downsides to using "threaded messages" instead of each message becoming its own new mail. To counter this, we sweep mail inboxes periodically, and clean anything older than 180 days/6 months. If you roleplay in inboxes and want to save those roleplays, please save them as you go, so you don't wind up missing data after we do the sweeps.