Platinum Gromit Badge for you Geezer.
Crime is bad in Johannesburg, but mainly in the predominantly poor areas, nowhere near the stadiums at Soccer City and Ellis Park. It is like saying the European Cup Final should not be staged in Manchester because people get shot in Moss side.
As for the other 9 venues outside of Johannesburg, the crime is not as bad, and again, the stadia are away from the worse areas.
I would be more worried about the BNP thugs who follow England, and their probable treatment by the South African Police if they step out of line.