I credited Trevor with everything below when it should have been his colleague Keith Jackson. Please read it accordingly. I am grateful to Constantin Basturea for pointing this out to me.
Trevor Cook, a PR man, is often a good read. He takes his profession pretty seriously although he seems an amiable chap too. (I've only ever encountered him through his blog, but it's probably a good guide.)
Just lately he's been jumping up and down about ethics in PR. He was galvanised by the 'astroturfing' - the setting up of phoney grass-roots campaigns. I've seen a lot of that in respect of 'network neutrality' - people who claim to be Joe Public who are actually paid lobbyists and the like.
Anyway. Trevor has tried to track down the ethical stance of various major PR firms. He's divided them into three classes according to his findings: tots, toddlers and walkers. (The last lot walk the talk. The others don't, to varying degrees.)
I won't tell you the winners or losers, Trevor deserves that privilege.