We once shipped a product (2011) which would delete user's account (and all his data) from the website when all they wanted to do is to 'unfollow' someone. It w

We once shipped a product (2011) which would delete user's account (and all his data) from the website when all they wanted to do is to 'unfollow' someone. It was hilarious issue of MySQL database issue, instead of deleting the record of the 'follow' it basically removed user's record and thus removing all their files and entries.