The verb "unfriend" is the New Oxford American Dictionary's Word of the Year for 2009. As in, “I decided to unfriend my roommate on Facebook after we had a fight.”
The official lexicographer has an interesting albeit brief quip about the word relating to modern technology and how its "un-" prefix is un-usual. Why is "unfriend" such a well-known trend this year? The concept of severing a form of communication with another isn't new to the Internet, let alone social networking sites which already host millions of people "friending" and "unfriending" each other. I suppose a better question, then: why is "unfriending" now more frequent or more public?
Perhaps unfriending is merely pruning the branches of a tree that cannot support every leaf. Abscission cells cut once-invaluable leaves and let them fall away so that the tree itself may continue to exist. A network with too much irrelevant input yields noise that drowns out the data from the smaller networks that we can afford to sustainably comprehend, threatening the communicative value of the whole.
The idea of unfriending seems appropriate and reasonable given the above assumption. Why then is "unfriending" the word of the year this year in particular? Perhaps it is because this year we have reached a time when enough people have reached a point of social network saturation and feel the need to publicly acknowledge as much.
When we announce that we have completed the process of "unfriendship" to the unpruned branches of our network, the remaining individuals are inclined to feel the pride of group-inclusion, even if they paid little attention to the communication of that network to begin with.
We boom with the idea of Internet-based social networking, extending to touch as many others as we can reach given the ease in establishing a connection. Now we're self-correcting, acknowledging the effort required to handle the sheer amount of potential content available to us. In order to actively engage, we must actively disengage. Focus makes it easier to contribute effectively.
Twitter's recently announced "Lists" feature is a euphemistic twin of the "unfriend" trend. Rather than applying exclusion to a master list of friends a la Facebook, Twitter is encouraging inclusion in tailored lists to funnel the ever-rising torrent of content. Both apply a similar mechanism to allow us to gain some noise control over our cultural vantage points.
Now given that there are inclusive and exclusive methods for social noise reduction, why is the exclusive term Oxford's Word of the Year? I suspect the eagerness to advertise the abscissive act of unfriending, a once-hushed topic now more widely socialized, has led to relaxed inhibitions regarding the use of the negative term and a desire to express and mentally justify what would otherwise be a hidden work of effort.