Yes you can and No it probably isn't legal.
What you'll have to do here is block quite a few sites and a lot of other things particularly relating to Kiddy Porn as if someone downloads the stuff from your Connection in most US States the ISP is Duty Bound to Report the Download so you as the person offering the connection will be held accountable for the Illegal action even if there is no Kiddy Porn on any of your personal computers. They will be seized subject to Forensic Investigation and you'll most likely find yourself sitting in a jail cell waiting the outcome of the investigation. Even if they do not find any of that stuff on your computers you are still responsible for the download and since you will be unlikely to tell the Police who was actually responsible for the down load you';; carry the can for it.
The next thing is that your ISP may specifically refuse to allow you to on-sell their services so it can also be illegal from that point of view as well.
This arose in a discussion on Unsecured Wireless Routers a couple of months ago and would apply here as well and the legal aspects are not just confined to Kiddy Porn but anything that the Homeland Security Act deems as suspect so you would be between a Rock and a Hard Place as you would never know what was suspect material and most of these decisions are personal ones made by low ranking Bureaucrats where you are guilty until you prove yourself innocent so it isn't worth the risk.
Of course if you are doing it for a company they will carry the can in the Legal Stakes and you can do it quite easily with 2003 SBS. But they will be paying considerably more for the privilege and have a Lawyer on retainer who specializes in this area of the LAW.
Col
