The Sufference Of The Political Parties

The party writing and postures on private walls and public places much to the loss and displeasure of house owners, are politicians right or might? If so, where it is mentioned? Walls are reserved much before an election by writing party names either as bold as they can write or with dirty paint, and even charcoal, thus spoiling the wall for long.
Why pasting postures every where cannot be banned? It is easy to trace the culprit and punish because the details are already in the postures. Why the authorities do not think of this? This will also go a long way if the intention is to beautify Chennai.