If downloading illegally uploaded content is illegal in your country - as it is in the US - then I have no problems with the authorities tying to crack down major offenders to discourage the act. The law is the law, and laws must be upheld. If you want different laws, you can vote. Your influence may be minimal, but that's just the way it is.
What I do have a problem with is private organisations taking it upon themselves to act as if they are government institutions, capable of sentencing individuals - without any form of trial. The RIAA and MPAA are prime examples of this; they are not part of the authorities, and as such, they should not be able to persecute people the way they do.
It might seem like an effective and efficient solution at first. Instead of having the often slow and bureaucratic authorities handle something like piracy, it should be done by a much more nimble and effective private organisation. This is the start of the slippery slope.
Then it gets ever slipperier. Because these organisations are not part of the authorities, there's no proper oversight. There is no democratically elected group or individual overseeing these organisations, which inevitably leads to abuse. I find it especially weird that the MPAA and RIAA have become so powerful in the US - I have this idyllic image in my head that Americans get to vote for everything, from president to crossing guard.
So, what does this slippery slope lead to? Well, people with little understanding of the MPAA and RIAA will certainly mistake them for government organisations, which is a dangerous outcome. Take the story of Coshocton, OH, a small town with free and open municipal wifi. A single movie was downloaded illegally using this wifi network - and the MPAA shut it down entirely.
Mike LaVigne, IT director, said that dozens, sometimes hundreds of people use the free service every day. On top of that, it uses a single address, making it near-impossible to determine the actual culprit.
From the story it is not entirely clear who shut the network down, but it appears that the network's administrator was spooked by the suits from the MPAA, probably accompanied by some threatening legal letters, and as a result, shut down the network.
All you people who advocate that companies like Apple or private organisations like the MPAA and RIAA should have control over your legally purchased products and internet connection: this is what you'll get. This is the world you're fighting for. I hope you're happy.