The US Supreme Court weighed in on VCRs in the 80s (IIRC), when the technology really became widespread and people could really start to copy shows.

What they basically concluded was that using a VCR to record TV was "time-shifting." This basically means that you can't watch a show at 8:30, so you record it and then watch it later. The Sup Court didn't see this is as stealing information and violating copyright. They felt that time-shifting was a perfectly legitimate way to, basically, violate those copyrights. You weren't stealing, you were making it possible for you to watch something that you'd otherwise miss.

I can't remember if that decision ever dealt with recording movies off i.e., HBO. For one thing, once a film hit cable tv, it might not be the same as recording a show that airs one day a week. For another thing, the Sup Court also didn't deal with using two vcrs to record a rented cassette (again, IIRC).

Now, the difference today is that the movies you watch (or download) online are ripped directly from a copy of the movie/show. Instead of copying something that is freely available on tv for one and all and watching it later, people are getting something that can only be bought (e.g., the dvd).

If you want to read an analogy that paragraph above, look at this way: pretend your apartment building overlooks a baseball stadium. Sitting on your rooftop and watching the game for free is something that will anger the stadium, but you're not really infringing on their "space" - their physical location. When it comes to watching a ripped dvd on the internet, that's actually a lot like sneaking into the stadium (or a movie theater) to watch.

As a final note, I really wonder what happened to the whole "time-shifting" thing. The sort of thing that people do nowadays certainly doesn't play out like it did before - "the show only airs once a week and then I can't watch it again until the reruns start."

As to the general copyright thing, it's much bigger than you'd think. Have you ever watched a baseball game? According to the announcement by the sportscasters, quoting the exact words they used to describe a play is a violation of their copyright. It's over the top and hard to police, but the general attitude is that if they don't make that dumb announcement while they broadcast, then they are basically abandoning their copyrights. There's not a lot of business concerns that liked that idea even 30 years ago, much less in today's hyper-corporate environment.

PS - if you ask a lot of copyright lawyers/teachers why the copyrights are so long, this is the answer you'll get: the copyright duration is extended every single time that Disney is in danger of losing its copyright in Mickey and the rest of Walt's wonderful original characters. Several law profs say, in fact, that the Digital Millenium Copyright Act should be called the Disney Millenium Copyright Act.