If you receive a message that someone shared a document with you from Google Drive, as of this moment DO NOT OPEN IT! It is a massive phishing scam that is going on all over the internet right now.
Just delete the email and then delete it from your deleted items folder. Hopefully we will have more to report as the details come out.
According to Google’s own system status page, the issue should be resolved.
This particular scam brings the user to a convincing Google Drive login page. Once you login, you are given the choice of what account you want to sign in with. Once a person clicks that, this is where the fun begins, because you’ve just given access to some hacker/scammer who can lock you out of your account, delete all your stuff, and fun things like that. You will know it’s a scam when you look in the from field in your email and it says: From:hhhhhhhhhhh
My recommendation is that for the rest of this week, do not open a thing from Google Docs that is shared via email. If by some chance you did click on the link, and you saw a screen of gobbledygook, then please change your Google password immediately.