Why can you only listen to top 40 radio stations from the US via their webstreams when you live in the US?

Ummm...If you know (or can find) the stream address, it doesn't matter where the station is, you should be able to stream it...unless the program or network you are using does not allow use of certain domains. So I, living is the US can listen to a Russian radio station playing club music that all sounds the same. But, in some places, like Burma, the government restricts access to foreign news sources. Or at work, a software firewall is used to block specific URLs that could be a threat, due to viruses, or that could simply distract me from my job...so if you just can't locate one...look harder...but if you actually can't play the stream...either there is a restriction, on the network probably, stopping you, or the stream is to much of a bandwidth hog, and your connection just can't handle the stream...Or Gremlins, that could be it too.