Lest we forget, .XXX will not be voluntary is some people have their ways:
According to the Congressional Research Service records:
In past Congresses, two bills were introduced to require the Department of Commerce to compel ICANN to establish a mandatory top level domain name
(such as .xxx) for material that is deemed ?harmful to minors.? The bills were S. 2426 (109th Congress), which was introduced by Senator Baucus, and S. 2137 (107th Congress), which was introduced by Senator Landrieu.
