Andy Abramson describes a security incident he experienced with the Skype Answering Machine.
A nice quote:
The bottom line is while this piece of software is not Skype’s own, how the program was able to clearly hear an and ease-drop on « encrypted » transmission is beyond my technical abilities, but it happened and the person on the other end told me too. But this begs the question of should you be using Skype for sensitive calls.
I would change that to « Should you be using VoIP for sensitive calls ?« . However, I think the security-related problems for VoIP are not necessarily tied to their technical implementation.
Remember the « old days », when email was not encrypted ? 😀 Do YOU encrypt your email ? 😉