The problem with visible identification on cycles is, I think, that people have some very f***ed up ideas about the rules of the road. I can imagine individual cyclists being targeted for perceived breaches.
I'm reminded of that differentpov chap from the Scooby Doo forum from a few months back. He wrote:-
Now, of course I can't condone the 3 abreast thing, or holding someone up for three miles (really?) but seriously, how hard is it to grasp? The rules of the road, generally, are 'don't be a dick' but so many people seem to take them to mean 'get out of my way'