Watching the headlines this week and we have already had two of the largest DDoS attacks ever recorded.
First GitHub was hit with a mind blowing 1.3Tbps attack and then this week, security firm Arbor Networks reported a 1.7Tbps attack against an unnamed US service provider.
Today it looks like ProtonMail (and ProtonVPN) are being targeted by a DDoS attack which is affecting people's ability to sign in or access their servers.
If you use ProtonMail, you may not be able to access your account as they sort this out. Till then, they are responsive on Twitter and posting status updates.
https://twitter.com/ProtonMail
https://twitter.com/ProtonVPN
Update : Looks like they are back online for the moment though mails might be delayed.
They also are posting service status here : http://protonstatus.com