“The patent (6449344), originally filed in 1997, and granted in September this year, gives AOL instant messaging subsidiary ICQ rights as the inventor of the popular IM Internet application. The patent covers anything resembling a network that lets multiple IM users see when other people are present and then communicate with them. “

— CNET.com
The problem with this, as anyone who ever used the Talk or Phone functions under Unix of Vax will tell you, is that the idea of messaging people is not new, and was not even when ICQ first appeared.