It happened to me yesterday. I switched from a network to another and the SE account got locked. Actually that helps an hacker or malevolent person (like an angry partner) to get into the SE account. If one manages to get into the email used for logging in FF XIV s/he just needs to try to login with the tethered mobile phone, thus changing the IP address and then reset the password from the email. It does more damage than the good it expects to achieve.