tower hamlets, camden, islington, bristol have all painted over or power washed Banksy and similar artists work. i recal a story of one where the council removed one that was actually on private property and the owner sued them.
what garbage, councils routinely destroy Banksy and others artist if its on their property, lest they are seen to allow graffiti. frankly its a good thing too, otherwise some places would be coverd by immitators and the style would lose its cache.
i dont believe that had a single complaint...