There is no such thing as an "IP scrambler". You can run through a proxy server under which you masquerade as that address, but I assure you, there is no way to "scramble" your IP and still be able to connect to networks (ie, the Internet, your LAN) and still receive data. Your IP address is what makes communication possible. When you load this page, you connect to an IP. Upon establishing a connection, the server sends data back through to your IP. More likely your local law enforcement simply didn't have the necessary provokation to expend what little resources they have, as well as gaining the necessary subpoenas for your contact information through your ISP.