Even if AIM or ICQ were the easiest to use or boasted the best features, it wouldn't matter. Unlike telephones, which connect to each other regardless of who made them, instant messaging clients only work with others of the same brand. Since AOL has the most users, all who want to chat with those people must become AOL customers themselves even if they prefer someone else's software. Microsoft and other competitors have tried hacking their way into AOL's network, but the company has aggressively defended its turf. Tribal Voice and iCast also filed a complaint with the FCC in April, accusing AOL of scuttling innovation and economic growth.
Instant messaging needs to be protected from the control of a single entity.
Federal regulators might be tempted to agree if only to avoid a repeat of Microsoft's antitrust battle. AOL's messaging dominance is as clear as Microsoft's PC operating system monopoly. That alone isn't illegal, but antitrust issues arise when a monopolist leverages its power in other markets. There are indications AOL could do just that. Instant messaging software is being discussed as a potential platform for a number of services, including phone call forwarding, location monitoring and most immediately content delivery.