The latest version of ICQ - 2001b (released November 4th 2001) contains a feature which enables users to share directories on their hard-drives with users on their contact list.
This feature is quite similar to the sharing capabilities of peer to peer networks and applications such as Napster, Gnutella, KaZaA, Audiogalaxy, etc.
The only difference between these networks and the ICQ implementation is the abilty to search for the files you wish to download. It is likely that future versions of ICQ will contain this feature, and will make ICQ join the mp3 and divX piracy world, also making Mirabilis a target to legal attacks from the RIAA and similarly oriented organizations.
But even before such a search service is implemented, the broad use of ICQ may make the directory sharing feature a replacement for current 'illegal' file distribution methods such as IRC xdcc bots and fserves, FTP sites, etc.