Cryptocurrencies are P2P so they can't be truly stopped, just like P2P piracy couldn't be stopped.
Centralized exchanges are about as big of a weakness as centralized public torrent sites are, but even that could be changed if the need for decentralized exchanges truly arises. Right now, decentralized exchanges have a big chicken and egg problem (you need sellers to buy, and viceversa). But if the top 10 cryptocurrency exchanges were shut down, the chicken and egg problem would disappear.
Centralized exchanges are about as big of a weakness as centralized public torrent sites are, but even that could be changed if the need for decentralized exchanges truly arises. Right now, decentralized exchanges have a big chicken and egg problem (you need sellers to buy, and viceversa). But if the top 10 cryptocurrency exchanges were shut down, the chicken and egg problem would disappear.