VM have been throttling for years, but I find it's one of the better policies, you lose some speed for a few hours and that's it. And there are no caps off-peak. It is unlimited, you can download as much as you want (within reason) but they just try to get people to do it when the network isn't as busy.
It's not like they're the only one, very few companies don't have some sort of FUP/AUP and Sky is no exception, from what I've heard if you hammer P2P downloads you'll get a warning then get booted off the network, but that's fair
IMO.