In the coming weeks we’re introducing a feature to keep your account safe from hijackers, even if they have your username and password. Now when we detect a suspicious login, users will be prompted to verify their identity by entering their phone number. Users who have not set up their phone number will see a place to do so in the coming weeks. Note that users can skip entering their phone number but may be asked to add their phone number again at a later date. Google will use that phone number to verify their identity upon the next suspicious login. Once a user verifies their identity the alert is dismissed. Note: the paragraph below was edited on June 12 to clarify impact to users logging in through SSO. Users with 2-Step Verification enabled will not be affected by this launch and will not see the interstitial to set up their phone number. Users logging in through SSO may see the interstitial to set up their phone number, but will not be challenged to verify their identity at this time. This feature will be slowly rolling out to Rapid and Scheduled release domains in the coming weeks. Release Track: Rapid release and Scheduled release. For more information: https://support.google.com/a/answer/6002699