Although the official line was always that it was an anti-piracy measure nobody ever though it was anything other than a way to stop people importing from other areas.
The "anti piracy" line is an absolute joke. Anyone who really wanted to set up a copying operation on a reasonable scale to sell illegal pirate DVDs would just make sure he had the right equipment to make a bit-by-bit duplicate of the disk. All the anti-piracy, anti-copying tricks will only prevent the casual copier from knocking out duplicates with regular domestic machines.
It was just the same with the old Macrovision anti-copying system on VHS tapes. The technique used worked well enough to deter casual users from just coupling two domestic VHS machines together and running off copies, but anyone with the slightest technical knowledge of how the system worked could easily defeat it.
But anything is possible on Tottenham Court Road! 
I don't know what the situation is like today, but 20 years ago you could often save yourself a substantial amount on Tottenham Court Rd. prices by jumping on a bus or the Underground and taking the short ride out to Edgware Road.
Lisle Street used to be the place in central London for all manner of surplus electronic stuff, but all the old radio "junk" shops disppeared from there years ago.
