When the Bit Defender Firewall detects that something is trying to access the Internet, it is automatically blocked until you give it permission. As you can see from the alert below, we were trying to log onto MSN Messenger when we got this pop-up alert. Bit Defender Internet Security will give you advise on whether or not you should allow the program to access the Internet. In this case we know MSN Messenger is safe, and as you can see from the screenshot, Bit Defender recommends that we allow it.