A post on the Call of Duty Community Website outlines details on PC online security, matchmaking and servers in Call of Duty: Black Ops 2, Treyarch's upcoming military shooter sequel. Here's a handy summary of key points courtesy of One Of Swords, where there's also a discussion of some of the negative backlash this has inspired:

• All servers are dedicated servers, used for public matchmaking and league play.
• There will be servers located around the globe.
• You can’t rent a dedicated server; they’re just free for your use.
• Anti-cheat is handled via VAC + Treyarch’s own proprietary tech working in tandem.
• Treyarch has a “full-time dedicated anti-cheat team” to police the servers.
• Server files will not be made available to the public. Treyarch runs them.
• Mods will not be supported.