Your problem is skype. There is a hack...i thought they fixed it..that allows you to get someones IP address if you know their skype id. Once some one has your ip it is not too hard to cause issue for you. The same is true if you use anything controlled by another user. Many times the person who pays for the server can get lots of information. This includes private game servers as well as the many audio conferencing systems. You need to be very careful what you log into. Many of the better systems even if you pay for them do not allow you access to people information. Servers hosted in someone house though you can do nothing about.
There really is not much you can do. VPN to a point will prevent this but a lot of system do...