my @me.com Email address password suddenly not working?

Hey folks, tried to check my emails this morning via my iPhone and Thunderbird and its saying my password is incorrect. I know its not as its saved automatically in both devices.

So gone onto iCloud to see if i can log in there and a notification pops up saying 'Your account has been disabled due to security reasons. To reset your account, visit ifogot.apple.com.

Has my account been hacked? Is this common? Thanks

James