Cyclists stay back! stickers

Yeah they are really starting to piss me off these stickers. They seem to be randomly placed on the back of most vans too nowadays, not even on the left. I don't get what they are supposed to achieve.
Might get a big placard attached to the bike that says 'Van drivers stay back'

I think there is a link to where you can get these ...here
http://www.theguardian.com/environment/bike-blog/2014/jun/12/the-madness-of-stay-back-cyclist-stickers#start-of-comments

sorry - here ...http://www.ctc.org.uk/news/cycling-and-safety-groups-restate-objections-to-tfl-sticker-on-vans-and-buses