Cultural Hegemony represents a Marxist philosophy that one social class among many rules over the others to prop itself up.
Cultural hegemony is the philosophic and sociological concept, originated by the Marxist philosopher Antonio Gramsci, that a culturally-diverse society can be ruled or dominated by one of its social classes. It is the dominance of one social group over another, e.g. the ruling class over all other classes. The ideas of the ruling class come to be seen as the norm; they are seen as universal ideologies, perceived to benefit everyone whilst only really benefiting the ruling class.
The weakness of such thinking is that there is no social mobility, and that individuals and organizations didn't work sufficiently to earn their wealth and position.
Administrators of Social Web Networks are a Ruling Class
There is merit in comparing social web business structures to cultural hegemony. The driving design purpose and intent of the networks is to maximize profits from an exponentially growing or ubiquitous user base, not to optimize distributed communication for groups.
Brad Burnham compares web services to governments, and I don't think he's far off in his analogy. Private property (a leased or owned web server) currently gives corporations the right to deny service to anyone at any time with little cause. Isolation is their justice system's penal enforcement. These networks tax their citizens attention to profit, in exchange for connectivity. Commoditization of social networks will drive this taxation to zero, forcing businesses to compete on value delivered to each member (smarter use of shared info, in a way that's sensitive to member privacy).
The technical development and scale of such networks has been proven by several large existing social networks: Friendster, Myspace, Facebook, Twitter, Google Buzz, & Open Source simulacrum Status.net, Identica, Cliqset. But not everyone can build and host such large social networks, so efforts have been made to encourage distributed social web options. But even in open source distributed systems data formats must be described and supported by the software, which is controlled by a small organization (social class) who's interests may diverge from members of the network. Cross compatibility may bind the creative hands of divergent designers. If you want to share data (read/write) on social network X you have to play by their rules.