Solipsism has a long and storied history as philosophies go. The basic premise is that because you cannot verify the existence of anything except your own self and thoughts, nothing else is necessarily true or real. It was almost inevitable that at least one digital intelligence descended from humans would find the idea convincing enough to adopt as their own. The problem with this is that in the age of modern Cognitech one can experience the inner life of the mind of another person from a first person perspective.
Not everybody is eager to share their very minds with someone just to convince them they're real, so most modern solipsists who take themselves seriously pack up and go do their own thing by themselves. Sometimes they'll make copies of themselves and network them so they can be sure they're real. However, enough solipsists have done so for them to gather together into chains of "confirmed existence" with whom they are willing to associate. For the most part they stick to themselves, design digital environments to inhabit, and arrange to protect themselves from "false data."
Solipsists can be found in most civilizations, but only tend to organize in ones with high numbers of neurally meshed or dataform citizens. They are more common among Logicians and younger Stored, but are irrelevant in the Union because their meshes make them acknowledge fellow citizens as real.
Benefit: Solipsists are highly resistant to Metatech assaults due to their refusal to acknowledge outside data or entities as real. Metatech persuasion attempts against Solipsists suffer a -2 penalty to the Metatech score unless the persuader has made their mindstate available in Lense form to them. If the persuader does this the benefit has no effect.
Core Value: Solipsism. Prevent people from convincing you of anything unless they can prove their existence to you "objectively" through the sharing and comparing of internal states. Interacting with and protecting anything you acknowledge as "real."