Eruv Online has an excellent series on the history of eruvin controversies. Specifically, the series traces the history over the use of 16 amot to define a reshut haRabbim. The discussion is enlightening in that it would appear that much of what some rely upon today has long been rejected. Furthermore, it is amazing to see how unaware many are of the history of the long-running eruv controversy when wading into the discussion.
Additionally, a discussion regarding the Gra’s (and his followers) opinion and the underpinnings of that opinion. Including, the rejection of the notion that legal precedent has the power to determine issues of Jewish law. That notion, the lack of binding precedent, is necessary to overturn the long-accepted practice of using 600,000 people to define reshut HaRabbim.