One of the most annoying things on the internet is when a website blocks content from people who are trying to see their content. This can come in many forms but the most annoying one, by far, is when you are forced to sign up before you can read anything. I can't think of any reason why you would actually sign up, unless the information you were looking for was going to save your life. Say you were choking and you needed to really find out how to give yourself the Heimlich maneuver. Perhaps then someone might actually sign up, and even in that scenario, you'd probably pass out before you could get through all the steps.