ISP's could easily stop Bitcoin, I don't really think anyone claims they can't? Bitcoin isn't mean to be an impossible to kill hydra of economic power, but a decentralized, peer-to-peer, trustworthy ledger of transactions. ISP's could block the common ports Bitcoin uses (but that would likely break a lot of other applications), they could potentially blacklist certain IP's, but because of the decentralized nature of…
Adding to this - ISPs likely would never try any of the above, simply because it would hurt their public perception, isn't worth the time, and is potentially illegal depending on the area.
in which countries?