I recently installed PeerGuardian, and it has blocked hundreds of attempts from several companies trying to ping my computer. Most of then occur while I have A P2p application open. Here are the last two IP address and names it blocked: 220.127.116.11 - National Aeronautics and Space Administration AP2P 18.104.22.168 - City of Halifax CITY-HALIFAX-NS-CA 22.214.171.124 - Miami-Dade County AP2P My question is why do these companies try to scan/ping my computer? What information do they gain from it? and how does that effect me? Thanks in advance.