This is really a very bad habit nowadays. Where ever they want they stick handbills and posters on public properties they don't even realize their mistake that actually it is spoiling their city's beauty and also it very unpleasant to see. they can solve this problem by adding their posters in newspapers, in the net and in many sites and many more things this will save the city from becoming dirty and also the city will more beautiful.
My views and opinions: Sticking posters on walls has both positive and negative sides. But, the negative effects over-powers or dominates the positive ones.
The public properties are an essential element of a state and we need to preserve them for our betterment. Sticking posters and handbills on the walls will only prove worse. Therefore, it should be prohibited. The government has to take every necessary step and action to protect the public properties, but, of course, with the aid of common people.
Solutions: Well, as true it is that the act will have negative effects, also it is no less true that posters are quite necessary, too. But, why not opt for banners? They could be hung on the walls and removed when not needed.