Radio's in a tough way when it comes to the internet; as you pointed out, they can't NOT be available to their audience.
At the same time, they don't want to pay the bandwidth bill to stream to listeners in Lithuania who is most certainly out of the 6-county survey area & isn't likely cared about by Bob Hurley Ford and Joe Marina Honda or the New Balance Store.
I don't have a good answer to this one. Do you limit your listening audience to a certain set of cell towers & zip codes & risk ticking off people on vacation, transplants to or from the market, & possibly an out of state owner of a local business, or do you open it all up & risk building an (expensive) fan club in Germany?
I've had this discussion with a station owner. It's not an easy decision to make.
Thankfully, so far most stations are at the least leaving themselves open to the continental U.S., & I think most are globally available.
Another problem arises when you realize these stations are trying to pay for their streams often with banner ads and pre-stream video ads. Trying to pull this in over a cell phone can easily break the system, either leaving them without the revenue to pay for your stream or you without the stream.
As a cell phone listener you are on the bleeding edge of technology. Which I applaud! If I had my way, internet radio would be factory-standard in every vehicle rolling off the assembly line next year. (There may not be too many, so that might not be too hard to accomplish. *rim shot*)
However, as a trail-blazer, you'll need to keep in mind there may be a few hiccups along the way, or the occasional app you'll need to download to make your phone & the internet streams "play nice." Normally these apps will only help you listen, not spam you or anything weird like that. I hope you'll give them a shot.
Some day, internet radio will be standard everywhere, & our grandkids will ask, "did you REALLY lose the signal when you left town?"
In the meantime, stations continue to work to make themselves available wherever & however they can... and, sometimes, it's not all smooth sailing. Hang in there, & keep trying!