Many sites use HTTPS by default: When you purchase an item online or log in to online banking, for instance, your browser will probably connect to the site via HTTPS automatically. But you can go one step further by enabling HTTPS on Facebook, Twitter, and Gmail.
To use Facebook’s HTTPS feature, log in to Facebook and click Account in the upper-right corner. Select Account Settings from the drop-down menu, and look for ‘Account Security’ on the resulting page. Under the Account Security heading, click Change, check the box next to Browse Facebook on a secure connection (https) whenever possible, and click Save.
To enable HTTPS on Gmail, log in to your account, click the gear icon in the upper-right corner, and select Mail Settings from the drop-down menu. Next, under the Browser Connection heading, select the button labeled Always use https. When you’re all set, scroll to the bottom of the page and click Save Changes. To learn more about Gmail security, see Google’s Gmail Security Checklist.