As Web companies strive to tailor their services (including news and search results) to our personal tastes, there鈥檚 a dangerous unintended consequence: we get trapped in a 鈥渇ilter bubble鈥 and don鈥檛 get exposed to information that could challenge or broaden our worldview. Eli Pariser argues powerfully that this will ultimately prove to be bad for us and bad for democracy.