The router has 2 DMZs. One for the Customer and one for the roaming customer. This DMZ can be breached almost as easily (At least the comcast ones) as WEP keys. If the user was doing home banking and investment or working from home, information can easily be accessed. Not only that but there is no Metering. A roamer could quite literally take all of your bandwidth. You would call Comcast and complain and they would say "There is nothing wrong on their end, it must be you" and you would be unable to prove otherwise.
You also shouldn't put much faith in the Declaration of Independence either as it was written by a bunch of criminals. Lets also ignore Australia, its an island of criminals. While we are at it, Zebras are born with criminal uniforms on them, lets ignore them too.