Source : Free On-Line Dictionary of Computing

ICQ
     
         1. Abbreviation for "I seek you".
     
        2. A proprietary {chat} system created by a couple of israeli
        guys, who later founded "mirabilis".  ICQ was sold to {America
        On-Line} around 1998.
     
        The name "ICQ" is a play on "cq", the radio signal for seeking
        conversation.
     
        {Home (http://www.icq.com/)}.
     
        [Confirm derivation?  TCP?  Summary?]
     
        (2000-04-03)