Is there such thing as a fake IP address and is it legal?

I guess yes, and no.  When you surf the Internet using stuff like proxies and VPNs, though the IP address is not your own, it does exist.  So this is a "fake IP address" in the sense that its not your real IP, but its also a real IP address in the sense that it does belong to a computer, somewhere in the world.  Using the term "fake" should perhaps be exchanged for "virtual" or "anonymous" because fake has some negative connotations to it.Though many users do take advantage of this kind of anonymity online, and use proxies and VPNs for illegal activity, not all do.  Perhaps the most common of these illegal activities would be credit card fraud, spam, and hacking.  These can also be used for privacy online, keeping your identity secret, and some users want to keep their ISP in the dark with regards to the "entertainment" that they enjoy.There are many legitimate reasons to surf with an anonymous IP address however.  Using a VPN to secure a connection with servers back at the office is a great way to keep outsiders from hacking your data.  When you're abroad, and connecting to public networks in countries you're not familiar in, having an IP address from your home country can make surfing the Internet a more comfortable experience.  If Internet censorship is blocking things like Facebook and Gmail, you can keep in touch with your family by staying invisible from repressive governments.There are also some gray areas that using a fake IP address can put you at an advantage.  Advertisers are pretty ruthless about tracking your online activity, which can be annoying. However, they do this to make ads more appealing and tailored to our needs.  I've actually seen some helpful ads, and might not have know about these services had Google not tireless tracked my online activity.  Downloading torrents with movies, music, and software, as well as exchanging these files over P2P networking sites is also a questionable activity.  Though some governments have outlawed it and others look down upon it, may people are still able to set up and operate these sites.  The jury is still out on whether its moral to file share.  Some look at it as piracy and outright stealing, while others see it as sharing stuff with friends, and a way to get a fan base (for the creators) for free.  After all, most people wouldn't buy half the stuff they download.So whatever your take is, using an anonymous IP address online doesn't have to be about being a bad guy. There are lots of uses now, and sure to be more in the future.