The gentleman here goes further into their website for their full feelings about the 2nd Amendment. There's a lot there, I just want to quote one bit:
We believe that the constitutional right to bear arms is primarily a collective one, intended mainly to protect the right of the states to maintain militias to assure their own freedom and security against the central government. In today's world, that idea is somewhat anachronistic and in any case would require weapons much more powerful than handguns or hunting rifles. The ACLU therefore believes that the Second Amendment does not confer an unlimited right upon individuals to own guns or other weapons nor does it prohibit reasonable regulation of gun ownership, such as licensing and registration. . . .
The question therefore is not whether to restrict arms ownership, but how much to restrict it. If that is a question left open by the Constitution, then it is a question for Congress to decide.
Gee, doesn't that just make you want to pick up your credit card and join them?