Although arguing that your IP was spoofed appears to be a compelling argument, here's some reasons why that wouldn't work.

Are you familiar with the act of perjury? Any person with the least amount of technical knowledge would know that spoofed ip addresses are only good for when you do not expect a reply to to data sent over the network. So, what that means in English is this, if you have a Web server that is excepting inbound connections and I am able to connect and began transferring data from your Web server then arguing that your IP was spoofed (someone else on the network was impersonating your Web server) would not make any sense.

I mean think of it this way, let's say that your phone number was (111) 111.1111
and my phone number was (222) 222.2222 and you want to impersonate me but you can't literally have my phone number (the phone switches know where the numbers physically terminate) in technical terms (the routers know where the IPs are) the most you can do is try to fool my caller ID system by forging my phone number (222)222.2222 when you make an outbound call. Now what happens if anybody tries to call you back? that's right, you guessed it they would call (222) 222.2222 which happens to be a real number that belongs to someone else.

So to the explain how this relates to arguing that your IP was spoofed.
Let's say that you were investigated and they found out that at IP address 172.16.0.1 on a particular date and that the particular time you were hosting infringing content.

Let's say that the aforementioned Ip address is yours, verified by the ISP who is the Administrative body for that IP address space (this is how you ended up in court in the first place.)

Your defense to these charges is someone must have forged my IP, which means that there was someone impersonating you on the network. Now, if this were true then what would have happened when they went to connect and investigate you based on Ip the address they would connect to your machine which has the right IP address. If you didn't have the files you would not be in court right now.

For the uninitiated, let me explain how this works so that you can tell all your friends. The companies that investigate the copyright infringement use a variety of means to verify who sharing what the simplest means of doing this is by connecting and downloading the portion of the content.

They send searches into the P2P network looking for queryhits on infringing content. They have databases with the hash values and file sizes of legit content this cuts down on the number of users sharing a text file as infringing content to try to trip up the investigators. after they received hit on the infringing file they make several attempts to connect to the host that is hosting the content to verify that it can be downloaded from that location. They use several IP addresses to do this.
They log the date, the time, the IP address and infringing content. Then they send a letter to your ISP. Your ISP forwards that letter to you for action.

Now, this wouldn't go any further if you just simply deleted the content responded both to the ISP complaint and the MPAA or RIAA complaint indicating compliance.


if you haven't noticed, the reason these companies have been able to win most of the law suits they've brought against companies and individuals is because they have valid legal arguments that hold up in court.

The one argument that they had that was a long shot and was rightfully struck down in court is that P2P technology in general contributes to piracy and is therefore subject to legal action.

when the truth is: people contribute to piracy and they use technology to do it but the people not the technology should be subject to legal action.

I'm glad this was settled in court.

__________________
Lee Evans, President
LeeWare Development
http://www.leeware.com