RTA isn't a tagging system as much as an attempt for the ASACP to interject itself into a political issue that just wasn't part of it's initial mandate. ASACP isn't suppose to be about keeping children from seeing porn, but rather keeping them from being IN porn. However, getting into the filter business is a slick way to try to get yourself into the political process, and Joan has never been shy about that, right or wrong.
Tagging is also pointless without support. All the tags in the world won't stop a single child from visiting an adult site if their parents don't take their responsibilities and set up their home PCs to use obey the tags.
It comes back to the basics of the problem, it isn't us, it's them.