If you're renting a film for $5 when it sells for $15 or $20, making a copy of it and then returning the flick, what you're taking part in is copyright infringement, the closest thing you can get to theft in this electronic world. The reason is that there are terms to renting, or even buying things like movies or software. Duplication is only permissible under copyright laws (In the US at least, I believe the WIPO has something similar but can't recall right now) when it is of something you own, for the purposes of personal backup.
The argument that there is no harm done to copyright holders is a back-and-forth one. On the one hand most people will argue that they wouldn't have purchased something regardless, so to them the companies have not lost a sale. But the other side to the argument is that if you're not willing to pay the set price for whatever it is you downloaded or copied, that you have absolutely no right to it whatsoever. It is the creator and owner of the work that has the legal right to dictate the method and means by which to distribute their work.
There's this prevailing attitude in the world now that if something is easily accessable, that it should be free on principle. If it can be obtained online, then by-god it should be free! It's a bad argument on every front. It's easy to obtain a gun and shoot someone. It's easy to smother a baby. It's easy to hit someone with your car. It's easy to do a lot of things you're not allowed to do, the fact that it's easy doesn't make it right. And on top of all of this, those who claim that it's OK to pirate because it's so easy go ape-shit crazy when a company starts putting complex DRM on media to make it harder for the average person to copy something. So it's OK for people to pirate because it's easy, but it's wrong for companies to try to protect their works?
Now, don't get me wrong, I hate DRM because it never works, and the only people it blocks are honest customers who by bad fortune don't have properly "supported" hardware or something like that. But that doesn't change the fact that it is the company's right to try and do that. Don't like it? Don't buy/listen/view it. Not liking it doesn't give you the moral right to then pirate it.
Now, is it a crime that causes a great deal of harm? No, not really. But that doesn't change the fact that it remains a crime. A lot of people who download movies, music, software etc are aware of that. The thing is, some people in this thread are lieing to themselves, trying to convince themselves that it is somehow justified because they don't like the business practices of the media companies, when in reality there's no real moral justification to it at all. You have no right to the works at all... period. Now, most here are aware of that by and large and have the attitude of "Yeah, I know it's illegal, but I accept the basic consequences of the act" Of the attitudes held by those who pirate, the second is by far the better.