We are sorry for our actual outage. We have turned the server off and we are investigating recent suspicious activities on some accounts.
OK - So at this point I would advise anyone who used the same username and password on Nucleus as somewhere else (which you shouldn't do in the first place - but people do...) to change their passwords. There is no point in speculating right now, but wouldn't you rather be safe than sorry?
Enabling 2FA is obviously a wise decision too, especially if you keep coin in escrow or use your account frequently.
never not use 2fa