block skype or VOIP out of your network
The analyst firm Info-Tech Research Group has recommended that enterprises ban the use and cites these vulnerabilities and issues with Skype:
- It claims that Skype's encryption is closed source and vulnerable to "man-in-the-middle attacks," and says it is unclear how well the encryption keys are managed.
- It claims that because Skype is not standards-compliant, it will allow attacks through corporate firewalls.
- It claims that Skype is "undetectable, untraceable, and unauditable," and so puts enterprises at risk with regard to compliance laws.
- It claims that the issue of whether VoIP calls "constitute a business record is a legal quagmire," and that "throwing Skype into the communications mix further clouds the issue."
and it eats away your bandwith
and as it works with a p2P model you don't know where the traffic is passing through and if someone is 'capturing' it.