Microsoft-acquired Skype ran into trouble when the company pushed an update which broke it on desktops. There was no effect on mobile or other devices. What broke Skype is unknown and that is the drawback of any other proprietary technology. Since you don't know what it does to your data, Skype is not recommended by free software advocates.

We recommend using Skype alternatives available for GNU/Linux systems. However, if you are adamant about using Skype on your GNU/Linux machine, the company has released a fix.
http://www.muktware.com/blogs/27/2011/1273