The Six Degrees patent, United States patent #6,175,831, "Method and apparatus for constructing a networking database and system", granted to Andrew Weinreich, et al., has been considered the definitive patent covering social networking by the owners of Tribe.net and LinkedIn. The patent claims covered the building of an online social network by having participants identify contacts who are related to them (i.e. their online friends), and then obtaining from each of these contacts a confirmation accepting the connection or not. The patent was sold along with SixDegrees to YouthStream Media Networks in 2000 and later to Reid Hoffman of LinkedIn and Mark Pincus of Zynga and Tribe.net for $700,000 at an auction in 2003. When explaining his reasoning for purchasing the Six Degrees patent, Ho