An 800-pound gorilla threw its weight into the security market today, and analysts say the impact could send the industry reeling in a whole new direction. IBM bought Internet Security Systems (ISS), one of the industry’s oldest and best-known independent security vendors, for a tidy $1.3 billion in cash. The security software vendor, which has been a supplier of point products for more than a decade, will be integrated into Big Blue’s managed security services business, transforming it from software vendor to service provider in a single move. With their joint entry into the managed services arena, IBM and ISS will challenge popular industry notions that such services are only for small businesses that lack security expertise, and that large enterprises would never consider handing over their security functions to an outsourcing vendor.