With the Syphon Filter: Logan's Shadow Demo, there is an hidden online mode. The online is called Combat Ops. Sony made the mistake of leaving the full game journal ini file on the game disk so you can now access the online mode. Currently, there is no master server set up at Sony so for now, it's Ad-Hoc only.
Here is how to access it.
1. Dump the demo to a "copy"
2. Rename the GAME_FR to GAME_DEMO and rename GAME_DEMO to GAME_FR with a certain editor
4. Launch the "Copy"
Here is a video of it in action. Don't mind the self-centered person that is talking.