When your credit card gets too much activity from random parts of the world, your bank usually shuts it off, or at least gives you a call to make sure all those charges are legit. Now, Google is implementing a similar strategy across all elements of your Google account: if the company detects what it considers to be suspicious logins for your Gmail, Google Calendar, Blogger, Buzz, or other Google accounts, it will flag your dashboard and let you decide how to proceed.
Google has been doing this for Gmail users for several months already, following the high-profile attack on Google's servers coming out of China. Numerous Gmail users—especially those who were of particular interest to the Chinese government—found that their accounts had been accessed by people overseas. As a result, Google decided it was a good time to start flagging users when their accounts were accessed from geographic locations that did not seem to be normal, and it has apparently been working so well that the company decided to add the feature to all Google accounts.