The point of bans like this is not to stop crime but to show the average voter/Potter fan that they are "doing something". Things that actually do work at solving crime like Harm reduction programs or youth programs are controversial ,expensive or both while a ban is no more expensive than the paper it is written on.
I have an idea for a UK legal tactical folder actually.
People need to understand that some crime is one of the prices we pay for living in a free society. When you start doing things like random searches you are no longer in a free society.
PC is just fascism for pussies!