OK, this is an edit because I want to be absolutely clear, my account is NOT compromised. I was asking this question out of curiosity, because I see many threads daily with people who's account is hijacked despite them having a good password and in some cases even a security token. I thought that if there was a way that people in that situation could at lest force the hijacker off their account, it would be helpful to them, which is why I posted the topic.
Someone posted something on another forum (not a million miles from here) suggesting that a man in the middle attack that obtains a valid session ID could permit an attacker to steal your session ID and connect to the game (without authenticating) using the stolen session ID. Apparently because the session ID has a long life span, it's possible to use it to launch/connect to the game without going through the login process.
Assuming that this does actually work, the attacker doesn't have your authentication information, only the session ID and your IP Address. I know that SE does check IP addresses for incoming sessions, so I would presume that if the session ID thing works, it must also involve spoofing the IP address of the client that the session ID was obtained from.
Anyway, all of that speculation aside, if you assume for the moment that it's possible to hijack a session ID and spoof the IP address in order to connect to FFXIV without authenticating. How does SE banning the compromised account help if the ban process doesn't force the player off the system and invalidate any session ID/key in use? I mean, it's quite apparent that the ban process doesn't in fact force players off the system because there are many, many examples of bots and RMT spambots that have been reported, but are still in-game untouched. Presumably they may already have been banned, but until the servers are bounced or the willingly logout, they can continue to do their thing.
So, here is the question, is there any way to force logout your own player/account? Can you do anything from MogStation or the SE account Information screen that has the consequence of forcing a logout? I know there is no specific option to do this anywhere, but if there was something players can do that has the effect of forcing your player off the server, it would be a way for those who have been compromised (but still have access to their account) to regain control.
Ideally, SE will alter their ban process to force banned accounts off the system and invalidate the session ID/key too. but unless and until they do, is there anything we can advise affected players to do that would help?