The servers crashed! 
Words from a Jmod:
Hi,
When a server crashes your character will be logged out but will
still be locked in that world until the sever can be brought back
on-line. This should only take a matter of minutes however in
extreme circumstances it can take hours.
You will be locked into the sever to prevent you losing any unsaved
information, in a worst case scenario the sever will perform a roll
back to the last known save which most of the time is just 15mins
before the sever crash. While locked in the effected account will
be unable to log into any other severs to prevent corruption of
your game data. You can still login with any other accounts you
have on available worlds.
It might appear that somebody else is using your account, but dont
worry nobody is 
Besides, I believe World 144 is back up and running already and
hopefully nobody should be having problems logging in any
more.
Hope this helps,
Mod Deakin.
Conclusion!!!! No more cws at w50! haha.