I think it is difficult for any working group to assume the responsibility
for assuring that everyone will do everything correctly in terms
of services, regardless of their location in the client-server chain. Yes,
things can be mis-used.
yes, but there's a difference between technologies that are accidentally
misused and technologies whose primary purpose seems to be abusive.
You might consider Ad insertion a mis-use others
who get reduced cost ISP because of them might feel differently.
check out the Opera browser or the Eudora mail reader. there are other ways
to put advertisements on somebody's screen without corrupting the content.
p.s. so if the ISP uses opes to insert advertisements, can I as a customer
of that ISP also use opes to remove them? if you say no, I claim you're
being unfair by putting the ISP's interest over *both* that of the content
provider and the consumer. if you say yes, I claim that opes is a useless
technology that serves only to increase operational complexity and to sell