Google Dashboard will now display a warning in red if there have been suspicious logins made to any of your Google accounts. Suspicious in this case means a login coming from outside the general geographic location of your normal IP address.

Dont worry: Google wont automatically shut you out just because you checked your Google Calendar in San Francisco before flying to Beijing. You get to decide whether the questionable login was kosher or not by either changing your password on the spot or dismissing the warning. If you want to know further details about the suspicious logins, Google even allows you to see a list of IP addresses that have recently accessed your account

https://arstechnica.com/tech-policy/news/2010/06/suspicious-login-protection-extended-to-all-google-accounts.ars