Can someone give a short, accurate explanation of what CISPA is about and how it's a threat? Unlike SOPA, where there was plenty of accurate information about

Can someone give a short, accurate explanation of what CISPA is about and how it's a threat? Unlike SOPA, where there was plenty of accurate information about why it was bad, I can't figure out what's going on with CISPA. For instance, reading the Wikipedia page it doesn't seem there's any obligation for companies to share information, nor a right to break privacy policies they couldn't earlier. So it's entirely unclear to me why my privacy is threatened. I'm pro-privacy but I want to know what there is to be worried about.