"the problem is that right now the common carrier status of ISPs is very nebulous."
Those who deliver snail mail have common carrier status but similar problems arise there. They
are not obliged to carry decomposing organic materials, live animals or hazardous substances.
They are not obliged to carry packages greater than a certain size or weight or combination.
They are allowed to sniff for explosives, narcotics and radioactive materials and xray suspect
packages. You also can't get an unlimited amount of mail into a post box designed for a
certain volume and have to make special arrangements for delivery or collection. The fact that
some but not all illegal packages can be detected by scanning does not make the snail mail
delivery companies responsible for illegal packages which can't be detected.
The nebulousness referred to is because sufficient and comprehensive case law does not yet
exist for much of what goes on in the relatively new ISP industry.