Wow! I am a "reputed" IT professional. Thanks a lot for awarding me with the title. Next time when I need a reference, I know where to look for it :)
Anyway. What do you mean by the interference?
1)IP packet sniffing? Surely many countries, USA inclusve do that, especially when it comes to sneak on bad guys. However, though it may seem easy on a small scale, large-scale packet snifing is a costly business. Do names like "Carnivour" or "Echelon" ring a bell for you? These are not Chinese or Russian systems. FYI, in Russia this thing is called "SORM", every ISP provider supposed to get hooked to this system. I guess the same thing applies to ISP providers in US or UK. Will this "SORM" thing spy on everyone? Impossible. It is like tapping every phone in town. However it may happen on a court order. But, IMHO, tapping e-mails and web traffic these days becomes less and less effective - https connections, encrypted traffic, software like PGP that uses 128-bit keys makes the tapped IP traffic useless, since it may take a considerable amount of time to decrypt the information.
2) Blocking foreign IP addresses? Lots of companies do that. Just FYI. Some US companies doing e-commerce will not accept IP addresses from outside US. However this is done via setting up a parameter in their website config files. Blocking content from abroad? Easy, provided that you have the firewall which every ISP in the country is obliged to use. (The idea seems a bit ridiculous to me). It is way easier for the government to oblige ISPs to do that. Lots of commercial companies will block certain IPs on their firewalls (say livejournal.com, playboy.com, etc). Easily done, easily bypassed through so-called access anonymizers. Go and check yourself at anonymizer.com.
What is the conclusion? The reality as always is less intriguing than human imagination.
But the key difference is, the US government is very hands off from the telecom infrastructure. And as for Eschelon, that ended up being largely cancelled. The FBI's far more modest efforts, since 9/11 have also been greatly scaled back. As for blocking, sure, individual corporations (and private citizens) do it here in the West, but in the East, governments are doing it.