You can't really use the defence that because you may buy in the future, it's ok to take it now.
Lets put all other data aside for a moment and just focus on music and video as these are the two most common types of files shared over p2p. If I connect to a p2p program and download some music and video, while downloading I'm sharing with others. Legally I'm breaking a law and some would say I'm stealing.
If I record a TV show onto tape and like it so much I want to share it with friends. Legally I'm violating the copyright and some would argue, I'm actually stealing from the creator of the show and all involved from staff to network.
If I listen to the radio and decide to tape some songs I like and give them a friend, again I'm breaking a law in my country and again many would have to call that theft.
The difference between the three scenarios is that with p2p, there is a very strong desire by companies like the RIAA with a lot of financial muscle to target it and try and raise the copyright violation to some level akin to a pirate company who makes mass copies of commercial music and video for sale. Turning it into a serious criminal offence.
The idea that you may buy some or all of what you download at some future point is still no defence in any of the above scenarios, it is a weak argument and no matter how hard you try to ignore it, in most countries, it is a copyright violation.
I'd argue personally that it was not theft but the RIAA, MPAA and other groups have put such a spin on this in recent years that its become difficult to seperate the idea of theft from a breach of copyright.
So I'm not going to defend p2p, just like I wouldn't defend TV, or the radio. I wouldn't defend my local library for giving me free access to books either. It is what it is and the whole idea of sharing has been with us much longer than any copyright law. It is in a very real way, a basic right we have to share and any law that overshadows that will never really be workable. In our society this doesn't in general, make it right or acceptable.
If I passed a law that I could own a river in a village and then passed a law that stated no one could take from the river unless they first paid me for the use of it. It is reasonable to expect that people would drink from it and defend their right to do so with arguments such as, I was going to pay for it later. It's not like I'm doing any harm, the water never goes down, its constantly flowing. I wouldn't have bought the water anyway. And so on.
Some people are going to the river, drinking from it and bringing water back for their friends.
Taking this further, some people setup stalls by the river to help people get access to the water more effeciently, even packaging the water. Some do this for free, some charge money for the time they invest in this.
The only real justification for this is to state that you believe the owner of the river has no right to own it in the first place. Despite the fact they may have put a lot of time and or money into keeping the river flowing or even creating the river in the first place. I know this is far from a perfect analogy but it serves enough of a purpose to illustrate the point I'm making.
So in the end we will all do what we want to do with regards to sharing but trying to make excuses for it above and beyond the desire to have it and or belief in your right to have it, is just as wrong as the act itself.
Would you drink from the river if you were thirsty?
