Google Moderator enables organizations to receive and select questions from audiences of any size. It uses a "wisdom of the crowds" paradigm of democracy. Questions for a virtual town hall style meeting are selected based on the number of votes they receive.
However, citizen participation is illusory when thousands of questions are submitted and only a few are answered. In addition, democracy supports minority and individual rights to be heard.
In live town hall meetings, questions are not voted for instead they are usually selected randomly ("You in the second row, do you have a question?"). Follow-up questions are almost always allowed.