Are you using gmail or G+ a lot? If so, do you use secure login ("two-step verification")?? You really should...don't take it from me, take it from +James Fallows
"Here it is: if you use Gmail, please use Google’s new “two-step verification” system
. In practice this means that to log into your account from any place other than your own computer, you have to enter an additional code, from Google, shown on your mobile phone. On your own computer, you enter a code only once every 30 days. ... In case you’ve missed the point: if you use Gmail, use this system.
Also, make sure the recovery information for your account—a backup e-mail address or cell phone where you can receive password-reset information—is current. Google uses these to verify that you are the real owner."
Basically, if you spend a lot of time online, read his article. It's well worth your time.
To turn on two-step verification (yes, I know we need to give it a better name and simplify signup): click on your name in the top right of your screen, click "Account Settings", then "Edit" on the "Using 2-step verification" line, and you'll be guided through the rest.