Why is it legal to record TV shows on a PVR hardrive, but illegal to download TV torrents?

Or is it?

because the law is old that's why.

the law hasn't caught up yet.

it's a general rule that if a law is abused by so many people as to make it un-enforcable and otherwise impractical then the law is changed and coped with, unless there are health reasons e.g. very bad drugs; but even then if everyone took cocaine then I think the government would be forced to look at it and put to scientists a case for designing a brand of cocaine where the ill effects (and therefore the cost to insurance and health services) were reduced.

it's already in the pipeline: the laws to do wtih personal downloads will change and enforcement of wholesale providers of illegal services will increase and that way the problem will solve itself.

in the long term i think it's time that the music business was not so corporate oriented because most of the industry just isn't made up of music makers or the like. torrent is a simpler and cheaper music provider, guerilla marketing is cheaper and more client based, once people realise that downloads aren't a bad thing and they aren't going away and that it can still be profitable if you can write a song and ask for a tiny fee for it to be paid to you (the musician personally, therefore doing away with most of the other people) then the face of the industry will change and we'll definitely have better music (I hope) because we just won't buy crap tunes the way we're forced to sometimes when we're attracted to just one or two good tunes out of x bad ones.