Many moons ago, the Brady Campaign had an open forum on their site. They shut down comments and eventually deleted them because it turned into one of the best locations for pro-firearm advocacy on the net. At one point, they claimed "150,000 internet grassroots advocates" based off of their e-mail alerts. I know that most pro-gun bloggers receive them so that number is considerably less.
Paul Helmke then moved over to Huffpo. We followed and the pro-rights comments still outnumber the anti's 10:1.
The Brady's also have a page on Facebook that has a forum for people who "join the group". The majority of the posts and threads are by pro-gun advocates w/ nary a Brady supporter to be heard.
So if 'gun control' is so popular, where are the supporters?