They're less dangerous than the rabid opposition who submits that because they are wrong about that, they are wrong about everything else, too.
I have relatively few problems with the paleolibertarians, and fewer still with the libertarians who are more in the lines of Ayn Rand and Robert Heinlein. All told, they are closer to the conservative ideals of limited government, adherence to the original intent of the Constitution, and individual rights than are the psuedo-conservatives, who are little more than liberals of the FDR-LBJ type, or RINOs.