No, I have some sites there but everything is ok.

Same here! Gonna contact 'm now.

just activated and moved about 5 sites to HG, so far it showing good performance. maybe you should ask hosting provider.

Just got in touch with them, here's the answer:

I do apologize for the inconvenience, I have confirmed that there was a recent critical update with cPanel. This particular update has caused some issues with the server. We are aware of it and have a fix that is currently running to bring the account back up. It shouldn't take more than a few more moments. We are running this fix in masse across all servers.

I have all my sites with HostGator. All are working properly.

I'd call the help desk.