NIS2010 & SKYPE (Voice and Video Calls)

Hi all,

Sorry I am not too sure if this topic has been discussed, could not find any information on it. 

My oversea friends was asking me to install SKYPE and use Video & Voice Call to "chat" with them.  However, I am not too sure if it is safe to use.

I was using Yahoo Messager (IM - Video & Voice features only) and NIS 2010 can configure to scan it, however, I am not too sure if SKYPE features are the same with Yahoo's, whereby NIS can Scan Yahoo messages. 

Does NIS scan video or voice calls via Computer (i think they call it VoIP)? 

I only use Video calls and NEVER type or download anything from Yahoo Messager.

Thank you for your time & Help.