Skype IM Privacy Settings

All you should have to do is go to file>options>Privacy> Then choose the options you want

• http://www.skype.com/security/safety/safety.html
• http://forum.skype.com/index.php?showtopic=360781&start=100&p=1766761&#entry1766761

and

Skype does not (and never has) prevented new users from sending requests to exchange contact details -- a feature to prevent such unsolicited approaches has been suggested many times

the privacy settings DO NOT apply to such requests, they apply to calls and IM

yes, a request to exchange details can include a reltively short introductory message and, yes, to a large degree, these messages LOOK like normal IM (especially if you collapse the upper section of the conversation window), but they are not

if your privacy is set to accept IM only from people on your contact list, this new user cannot send you any more regular IM, they cannot call you, they cannot send you files, and they canoot see your profile details or your online status

if they send you another request to exchange details (assuming you haven't blocked them already) they can include more introductory message

yes, if they create a new Skype Name, they can bug you some more, but there is also a way to report such abuse to Skype

that's how it is and how it always has been

(source: http://forum.skype.com/index.php?s=584f1120c3106d873a348ce7b4a12748&showtopic=350191&mode=threaded)

This is default behavior with Skype. Unfortunately if they limit friend requests, they would render the tool unusable for some users. This is annoying at times, however a some point your contact info will get purged from the spammers lists if you fail to respond.