Part of the disadvantage is that any user of a P2P network can instantly join the network, and then immediately "rat out" any other peer he comes across.
If a network is totally closed off, with a single point of entry, one would first have to take down or infiltrate that single point. For example, if a hypothetical illicit VPN was created, hosted by a large server in Serbia, criminals in the US could tunnel their traffic through chains of proxies, with this VPN server at the end of the chain. US law enforcement would have quite a bit of trouble seeing the internals of this network, at least without significant social engineering and investigation.
If a network is freely joinable and is a "panopticon" (everyone can see everyone else), investigation into the network can be done by anyone anywhere, with ease. What IP addresses are connected, how much data and what kind of data nodes are sending, etc.
In general I agree though. The Bitcoin network and protocol is strong and well-designed, and assuming major governments do not ever outlaw the use of the Bitcoin protocol itself (and they probably won't), it should remain strong for a long time. Bitcoin exchanges are definitely the weakest link.
Comments
Part of the disadvantage is that any user of a P2P network can instantly join the network, and then immediately "rat out" any other peer he comes across.
If a network is totally closed off, with a single point of entry, one would first have to take down or infiltrate that single point. For example, if a hypothetical illicit VPN was created, hosted by a large server in Serbia, criminals in the US could tunnel their traffic through chains of proxies, with this VPN server at the end of the chain. US law enforcement would have quite a bit of trouble seeing the internals of this network, at least without significant social engineering and investigation.
If a network is freely joinable and is a "panopticon" (everyone can see everyone else), investigation into the network can be done by anyone anywhere, with ease. What IP addresses are connected, how much data and what kind of data nodes are sending, etc.
In general I agree though. The Bitcoin network and protocol is strong and well-designed, and assuming major governments do not ever outlaw the use of the Bitcoin protocol itself (and they probably won't), it should remain strong for a long time. Bitcoin exchanges are definitely the weakest link.