Definition: Given a 'poster' sentence and a corresponding 'response' (often, from Facebook or Reddit)classify the sentiment of the given response into four categories: 1) Positive, 2) Negative, 3) Neutral, and 4) Mixed if it contains both positive and negative.
Input: Poster: Tonight I was proud to join other high tech champions for a "Celebration of Internet Freedom" at the Newseum in Washington, DC, to mark the 1st anniversary of SOPA.  Responser: Rep. Lofgren, please read this well thought-out post and think of ways to improve your proposed "Aarons Law" http://www.volokh.com/2013/01/16/the-criminal-charges-against-aaron-swartz-part-2-prosecutorial-discretion/
