PeerBlock was imagined as a totally new concept in personal computer protection. The security it provides comes from the fact that it blocks any connection to known _bad’ peers. And by peers, the program understands hacked computers, spyware orientated servers, machines that monitor p2p activities, sent information, and ‘ undoubtedly important ‘ entire countries. In this way, prevention has been taken up to a new level, as no upcoming data or no one way connections to potentially dangerous servers will be possible anymore. Working as an IP blocker, this firewall comes with a library of _bad’ IP addresses and can be controlled by users by checking or un-checking a list of options. One downfall is the possible blocking of a website that is on the white list just because it is hosted on a server that has its IPs on the black list.