Strictly no spelling zone

Jon C tells me that he found this Peterborough sign in a house window fronting the pavement.

Clearly it's aimed at people outside the house rather than inside.

So, is the house owner expecting all smokers who happen to be walking past to put out their cigs?

And how far out into the street does the owner expect the zone to extend?

If the sign is to be effective, perhaps the owner should mark out the area exackly.