What's the trouble with VOIP?
Sure voip is cheap and on the verge of becoming ubiquitous, but there's one thing that a lot of people are missing. It's not something that most people think about, but the fact that the phone companies own your landlines provides you a great deal of security. No one can eavesdrop on your phone conversations without the active approval of the phone companies. Even governments need to get the telco's approval to tap your line.
Not so with voip. It's not even funny as to how easy it is to subvert network traffic or even to listen in. All of a sudden it's easy for the mob to figure out the restaurant doesn't intend to pay any protection. Suddenly the NSA really could be listening to everything. Hell, even the neighborhoor kid could.
The only solution would be to make sure that all voip conversations start and end on encrypting phones. The economics of how that works out would be interesting. Perhaps we'd go back to a situation where the phone companies can make more money off the equipment than the transmission medium.