Some users claimed that their accounts were hacked regardless of whether they had 2FA enabled. How much truth there is in that is hard to say, but something definitely turned bad at some point, and those who could only explain what was happening disappeared without a trace.
I was one of those unfortunately. You can read here what happened to me
https://bitcointalk.org/index.php?topic=320959.msg65765181#msg65765181 (No need for reposting).