Wire tapping on the internet

The move towards Internet telephony seems to suggest a new line of security issues. Given the extensive use of Skype and other internet telephony tools, due to their inherent economical costs, it is but natural to ponder  on how vulnerable are these channels.

Wire tapping or eavesdropping into conversations has always been a human and government fad. In the  traditional setup, you need to attach a tapping device to the phone to listen in. In the world of Internet telephony, I wonder how easy it is to put a device on a server and get direct access to millions of conversations.

I am sure the security agencies must be pleased to see conversations moving through the internet. If it is convenient for security agencies to access conversations on cyber space, it must be equally the same rule for criminals to eavesdrop as well.

Again, what laws and regulations will apply to wire tapping on the Net? Surveillance laws are generally restricted to a country level. How does one regulate the entire gamut of internet telephony effectively?

Any suggestions or thoughts from anyone?