Lawsuits will fix this. They can block competition, yet offer the same service? So in turn it is price fixing. Block the pepsi truck from getting to the store, so Coke can charge more money at the store. (maybe not the best example, but you know what I mean)
For those that say Vonage sucks, I have had it for 2 years now and it works great. It is has its issues, but nothing more than a regular more expensive land line does.