Mira este vídeo fascinante, sobre la historia del CAPTCHA, que usan unos 200 millones de personas al día... Lo explica uno de sus creadores. TIENES SUBTÍTULOS EN ESPAÑOL. PUEDES ACTIVARLOS.
Your personal learning network can act as a filter to help you with everything from avoiding information overload to getting a recommendation for a good restaurant. Digital filters can also create problems, keeping you from seeing the whole picture about a current or historical event, or even missing out on a great new movie because nobody you know has seen it. In the following TED Talk, Eli Pariser talks about the dangers of online "filter bubbles".