When a user deletes their post or comment then deletes their account, previously deleted content is deleted from the database. Note that you need to delete the post or comment before deleting your account. There is not currently an option to easily delete all your submissions without going through your history.

IP addresses are logged and those logs are deleted after a month. We could change that someday or not depending on the ban evasion we deal with. We don’t log anything else.

Yeh I’m getting more concerned with this with kiwi farms :/