To be perfectly honest, nearly everyone I know has a facebook; my best friend, that guy I took some class with, my dad, my old boss, my aunt, my high school teacher, my mom (even though I made her take it down as soon as she registered). Oh! And lets not forget Target, Apple, and Gossip Girl. Like I said, more or less EVERYONE I know has a facebook and then some. But at what point does everyone's involvement in social networks such as facebook take away from what teens joined them for. Teens join these social networks to "see and be seen" according to Greg Anderson (http://adage.com/cmostrategy/article?article_id=127430), so adult invasions seem a bit out of place. When most people hear my dad has a facebook (which he uses regularly I might add) I get a funny look and then a "And you're his friend? what happens if he sees your pictures? OMG" While I don't think it is all that weird, I definitely understand why my friends do.
While being friends with relatives on facebook is one thing, social networking is taken to a whole new level when brands and advertising get involved. Currently marketers think that to not have a facebook means missing out on the latest advertising tool. Brands see social networking as trendy, teens see their involvement as intrusive. Corporations are invading their space, pushing them out of it. Because of this invasion, teens are fleeing to different websites and social arenas, looking to avoid the unsolicited marketing in their social lives.
What is important to think about is what is appropriate based on your brand. For example, Apple has successfully been on facebook. Facebook holds a good portion of their demographic and Apple has a lot of user generated content on their page. Yet a company such as Pizza Hut is just taking up space and time in the teens social climate. When looking to discover the newest and latest marketing idea remember the brand. Remember that getting the message across is most important. The goal is not to push away the consumer. Additionally, just because the latest thing, is, well, is the latest thing and everyone wants to get involved, doesn't mean it is an appropriate idea. Just stay true to your brand and let it guide you in a way that makes sense.