Un- or de-, it's still getting rid of them

Rico says he's been unfriended by some friends of late, so he knows the behavior, but Jillian Rayfield covers the issue for TPM LiveWire:

The New Oxford American Dictionary announced today on its blog that the 2009 Word Of The Year is "unfriend."

Unfriend; verb: To remove someone as a 'friend' on a social networking site such as Facebook. As in, 'I decided to unfriend my roommate on Facebook after we had a fight.'

According to Christine Lindberg, Senior Lexicographer for Oxford's U.S. dictionary program, "unfriend" was chosen because "it has both currency and potential longevity".
She continues:

In the online social networking context, its meaning is understood, so its adoption as a modern verb form makes this an interesting choice for Word of the Year. Most "un-" prefixed words are adjectives (unacceptable, unpleasant), and there are certainly some familiar "un-" verbs (uncap, unpack), but "unfriend" is different from the norm. It assumes a verb sense of "friend" that is really not used (at least not since maybe the 17th century!).

Other words considered for the top prize were "hashtag", "funemployed", "birther", "death panel", teabagger", and "tramp stamp." The post also lists "notable word clusters for 2009," which features variations of "Twitter" (like "Tweeps" and "Twitterati"), and Obama (like "Obamanomics" and "Obamalicious").
"Unfriend" joins the ranks of previous Oxford winners, including 2008's "hypermiling" ("to attempt to maximize gas mileage by making fuel-conserving adjustments to one's car and one's driving techniques"), 2007 winner "locavore" ("a trend in using locally grown ingredients, taking advantage of seasonally available foodstuffs that can be bought and prepared without the need for extra preservatives"), and 2006's "carbon neutral" (the calculation of "your total climate-damaging carbon emissions, reducing them where possible, and then balancing your remaining emissions, often by purchasing a carbon offset: paying to plant new trees or investing in 'green' technologies such as solar and wind power").
Lindberg concludes of the decision: "Unfriend has real lex-appeal."

Rico says he agrees with a commenter that 'defriend' (as in defrag and defuse) is a better word, but the pundits didn't agree...