VoIP security

[Seth Art <sethart () gmail com>]

My coworker had an interesting question.  She had to validate her
credit card number over the phone using her social and other sensitive
information.  She has a VoIP router from her ISP.  The question: Are
the VoIP packets encrypted as they go across the wire?   Or can
someone sniffing in the right place capture all of that sensitive VoIP
traffic and reassemble her CC# and SS# from the tones? Is this
somethign that might be an issue in the future or is there already an
answer out there?

-Seth