My battle.net account was locked yesterday due to suspicious activity. I only got an account for Diablo Ultimate Evil on PS4 and set it up with my generic, least secure password that's probably floating around in the internet ether from one hack or another.
Didn't see any mention of any other widespread issues.
There is a note on all of their games log in that they are experiencing 'issues'. It's almost certainly a DDOS because I've never ever EVER had a log in queue just from trying to use the B.net launcher.