"... with broadband service, one's computer is online all the time and it has a stable identity."

well, it 'can' be, if you let it. My broadband cable modem has a little button you can push, and two of the 4 green lights go out and nothing gets thru. (My wife makes me turn it off at night, even with the computer off).Plus, I use a firewall that allows me to "stop all traffic" with one click. The firewall also is set to be the first thing to load, even during boot-up, so that nothing can get in while things are starting. Two years with cable, and absolutely NO problems.


I also use online banking, and it uses very safe protocalls to ensure anything I'm doing there is protected.