Actually, they reroute your internet traffic, so it does more than "mask" your IP address... it's just a selling point to "mask" the IP address. While it is true that your IP address is still used, it takes it out of your daily internet connecting, so those who are looking for it have to jump through more hoops. Not getting a VPN because one person has your IP address is a bad reason to not use one. Also, most free VPNs are crap, have security loopholes, and minimal bandwidth. Using a free VPN is no better than using a proxy... unless you can find a quality one. It's rare to find free accounts for quality VPNs, but I have one. Just keep your eyes open, or pay the $4/month if you want to keep your IP address properly concealed to avoid more problems.