James, Anchor Free is the name of a company that publishes a free software program that when activated makes the other Internet servers think you are somewhere you're not. In this case it makes it look as if you are in the UK. The actual program is called 'Expat Shield'.
Since the BBC iPlayer only works in the UK one can see the advantage of having them think that's where you are.
Don't tell them I sent you.
Dave
PS: If there are enough interested parties contact me & I'll set up a group lesson on this software & how to use it.