By default, Skype allows people outside your contact list to IM you. You can change your privacy settings to disallow that.
You can add location information to your Tweets, such as your city or precise location, from the web and via third-party applications. You always have the option to delete your Tweet location history. Learn more
By default, Skype allows people outside your contact list to IM you. You can change your privacy settings to disallow that.