This worm has turned

I am sure that all those of you who live in towns have seen cars like this.
 
This particular car has been parked in a street near me for at least two months. It has not moved during that time. (I have checked and yes, it is taxed and has an MOT) That sign is clamped to the roof with a metal bracket.
 
 
The law says that if a vehicle is principally for the display of advertisements then “Advertisment consent” is needed. 
It is actually a criminal offence to display an advertisement without consent.
 
I don’t know how you check on such “consent” but I seriously doubt whether the police or council would be interested in taking up the case.
 
So I opted for a bit of direct action.
 
The top two photos are “Before” and the lower two “After”
 
Spot the difference between the two telephone numbers.
 
Arise citizens! Pick up your felt tip pens!