I think it's safe to say that most of us here are against nannyism. At least I know I am. But I do also recognize that there is very little, at all, that can be done to fight the system so to speak. The wheels of the legislature are far too powerful for even the 2-3million of us to fight against. Less than 1% of the population spread out over the whole country can't swing elections one way or the other. Of course, that can be read as fatalistic or rational, depending on ones perspective. The factors which drive a body to create a law are so deeply embedded in the way we perceive legislation in this country that it would take essentially an overhaul of the entire system before any real change to the nannyism factor would be evident. Most americans, most of the time, don't mind the paternalistic state. Rather, they feel safer with it. I draw this inference from the plain fact that if it weren't the case we would see a very different form of politics and laws. To steal a concept, the thing speaks for itself. As much as we blame the politicians, the American public are the ones who put them in office.
Further, while I agree that banning a product does seem... unAmerican, it's actually fully within the realm of the Congress. Our own Constitution gives them the power to regulate for the health and safety of the citizens.
That being said, I really don't foresee a complete ban on tobacco. The lobby, while focused on cigarettes, is extremely powerful. Realize this is the same industry which defrauded the American public for decades, induced millions to smoke and stay smoking, and they got a relative slap on the wrist (see what happens when a fellow kills even 2 or 3 people, down here in the belt it's time for a very short injection. In comparison, the many millions killed by big tobacco and the fines seem... inconsequential). I am speaking not of our wonderful pipe tobacco blenders, but rather the big companies like RJR or PM. I am not trying to attack big tobacco, merely evidencing the power of the tobacco lobby.
The health tax on the state level is the most likely possibility, at least from my perspective. I'd be surprised if we see a full on federal regulation actually attempt to control the flow of a legal product over state lines; the policing aspects are mind boggling, especially with so many other issues plaguing the feds (drugs, firearms, etc). Plus there are some pretty good constitutional arguments to be made if that goes down. Likewise, a total restraint of legal products crossing state boundaries raises a number of constitutional issues; partial restraint is allowable (see MartinH's reference to alcohol). They've tried to do a total ban in other sectors (milk, lumber, etc) and have been swatted down by the Supreme Court. Short of a federal ban, we'll still be able to get our tobacco, just at a ridiculous price. And, of course, the feds can decide to tax it too.
Which returns us to Ebay and the original concern; the use of the loophole and it's potential negative impact on all pipe smokers, not just the ones who choose to utilize the service. Of course they have the right to do this; it's none of my business what folks do. I think the point is less in the advocacy of restriction by externalities (IE, us) and more of a self restriction for the greater good. The more fuel we give the anti-smokers the more likely it becomes that we'll be restricted. To me it's like a kettle set to boil; it'll boil regardless, all we can control is how fast.