Enable HTTPS (Hypertext Transfer Protocol Secure) option in your facebook account

Hypertext Transfer Protocol Secure is helping us to make our browsing safe so please check whether you have activated https secure browsing option in your facebook account to avoid insecure browsing.

To enable that service:
Go to Account Settings
Select Security
Click on the Edit option in Secure browsing line
Check the Enable check box
Save the settings

if you want, you can use other options too, to make your account very safe.
Try to do the same thing in other social networks.