... now, every man (and woman) and their dog are cycling.
You know, I didn't believe you, but then I Googled, and now have to admit you're right:
Seriously, though, regarding the OP's comment about cyclists getting a bad name for littering: I think this is just a symptom of all cyclists being tarred with the same brush when a minority of them do something wrong, e.g. break a road law, behave like an idiot, or litter. Do we assume that all motorists litter because some of them do? Or make the same generalisation for pedestrians? The reason people make such generalisations for cyclists is that we're still a minority group, and its human nature, unfortunately, to pick on minority groups. So my response to anyone complaining about a cyclist littering (or doing anything else wrong) is to ask them what relevance their mode of transport has to the offending behaviour.