I Tweeted yesterday about a New York Times article:
"I hate Ticketmaster - "Ticketmaster Settles With F.T.C. Over Springsteen Tickets" http://nyti.ms/aUZMHo"
I got a response from a service called Amplicate, which pulls together positive and negative comments about brands. It made a page called Ticketmaster Rocks, where it collected supposedly positive Tweets about Ticketmaster, and one called Ticketmaster Sucks, where it collected negative Tweets.
But if you look at the Ticketmaster Rocks page, most are negative. The service cannot distinguish sarcasm. Take a look: