Alerts about specific security issues requiring immediate attention - regardless of location / provider (e.g. including notices for 3rd parties)
Twitter discovered an issue in their logging which had the potential to leak password data - out of caution they are recommending people change their passwords, particularly if this password may have been used in more than one location. Details of the annoucement follow below including notes on avoiding phishing emails.
The thing I have always loved most about the Internet is the way it can be a great equalizer. One person with a good idea can reach masses they would never be able to by traditional physical means.
And here's one great idea. https://haveibeenpwned.com/