From The Danger Room:
The New York Times makes it sound like something brand new, because the Mumbai terrorists did it. But for years, bad actors have been using Skype, Vonage, and other Voice over Internet Protocol (VoIP) phone services to keep their communications private.
Not only does Skype use some rather nasty encryption algorithms. But IP-based calls can be bounced around the world, far from switching stations; identities can be easily spoofed.
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My Comment: Personally .... I love Skype and Apple Ichat.