The internet is supposed to be a bastion of self-expression, where you're free to speak your mind knowing that someone, somewhere shares your feelings. However, Pew Research and Rutgers University have published a study showing that many social network users feel compelled to keep their mouths shut on sensitive topics. While the majority of those studied say they'd be willing to discuss a political issue like US government surveillance at dinner or at work, they're very shy about doing the same on Facebook or Twitter. Effectively, the internet is mirroring the real world -- people face a "spiral of silence" where they're afraid to share opinions that differ from those of their friends. That's borne out by additional findings that people suspect they have more disagreements with their online buddies than their personal acquaintances.