This is not surprising at all…but still disturbing. Unfortunately, Skype is not free software. An effect of this is that users are denied the freedom to modify Skype in order to stop it from snooping. The article indicates that users are installing secondary software in an attempt to combat this. However, the ability to modify your own software is the best defense.
Although the network effect of Skype is strong thus making it inconvenient to ignore, I encourage users to try free alternatives. For example, Ekiga.