I am sure this is everywhere. I found it through the journalist Mike Butcher who wrote (and is updating):
The map is a sea of red pins, indicating that there are in fact BNP members spread pretty widely across the UK. London is barely visible under the map. Zooming out means that the map can no longer render all the data points adequately. It’s worth remembering that Britain is in fact one of the least racist, most tolerant nations in Europe, but the map looks pretty scary covered in these large red pins.