In France, there is a law stating that all handsets must be unlocked to use on any carrier. Luckily for people in the UK, France is a walk around the block.
Apple is trying their best to keep people from the UK from going to France and buying unlocked iPhones. I don't know who would want a new18 month contract with any carrier, rather than an unlocked iPhone.
Though the majority of customers buying an iPhone on O2 probably wont use a jailbreak or unlock their phones, a huge majority of hackers, people who want an iPhone on a different carrier, and people who want more functionality may indeed take a road trip to France.
“I don’t know who would want a new18 month contract with any carrier, rather than an unlocked iPhone.”
Maybe someone who wants to save a couple hundred pounds in currency conversion and unlocked premium…
“Luckily for people in the UK, France is a walk around the block.” ???
Not for people in the UK, but it is for the germans. :-)