Screeb: From their AUP:
3.2.1. Virgin Media does not place a limit on monthly network usage. However, in isolated cases (currently less than 0.1% of customers) where excessive network usage at busy times (9am to 9pm) is having a detrimental effect on other users, we may need to take appropriate action in accordance with the terms of this AUP to notify users of the impact they are having and require them to move some of their activity into the less busy period.
The throttling seems to be an automatic way of dealing with this (instead of the "notify" bit they mention in the AUP), and it is currently being trialled.
And you think they do what? They ask the users "to move some of their activity" and if it doesn't happen then next step is cutting the user. So where's the unlimited?
As for the your "FFS" and "pulling crap out of your arse" I did find their T&Cs and posted that they do have a policy on that - which is exactly what you described.