Are you sure that the policy wasn't designed to transfer control of the outdoor advertising industry to a subset of advertisers? You know... ban advertising, and kill off the existing outdoor-ad only companies. Then reintroduce outdoor advertising, granting permits only to some group of "respectable" advertisers.

I'm not saying that this is the case here, but it's a fair question, I think.

[Edit: Here is an older but more-balanced article from the BBC: http://news.bbc.co.uk/2/hi/business/5355692.stm]