In reply to danm:
I think there's no magic bullet with Font being so close to Paris (i.e so accessible). Besides it's not just climbers crowding the place, go to Dame Jouanne on a Sunday and you'll see children running around, hikers, horseriders.
Litter is a HUGE problem. Yesterday I went to Restant du long rocher for the first one (great place by the way, though moss is coming back...) and found a printer and two PC towers off a "path". There's actually an observatory to report this and other violations (like construction firms dumping rubble and other waste). But in the long run I don't know what we can do as it's a question of changing people's mindset, which takes generations to accomplish. I'm convinced it's about the culture; I'm pretty sure theses discharges of rubbish would never happen in a country like Norway for instance. In terms of measures, I was thinking maybe rangers could roam around the forest.
In terms of good unpopular venues, I haven't been to all of them yet but I suggest just trying those close to popular areas that will likely sport similar features. So, instead of going to Roche aux sabots, why not go to 95.2, 91.1, Rocher Guichot, Rocher fin, Potala... If you want lots of problems, Rocher d'Avon is a big area (divided in three sections in the 5+6 guidebook), though a bit mossy. Mont Aigu is on the other side of the Gorges de Franchard and has lots of cool problems too; etc etc. Again these are not hidden areas! I'm not a big fan of hacking my way through the forest myself. But I think it would be good to just divert part of the flow of climbers towards contiguous areas (Cuisinière/Isatis> Sablons/Haute-Plaines/Raymond/Meyer).
Trangia: Yeh I can see why one would be sickened by all this. Plus everyone comes around the same time (which is fair since winter, despite being amazing in terms of friction, is veeeeeeery unstable weatherwise - not to mention the presence of those darned hunters). But this winter I've managed to spend an entire afternoon alone in L'éléphant, so it's feasible if you're willing to risk being stranded because of rain...
mrchewy: I think an awful lot more climbers flock to Font than to the Peak District, the human pressure cannot be compared. And like I said, I'm not demonizing anyone (I've lived long enough in Britain to see beyond the Anglo-French "rivalry"
), I'm just saying that I've seen much more foreigners than locals climbing (I was actually extremely surprised by that), which is why I'm trying to reach people who only come on and off and might no be aware about the rules and the consequences of their attitude. I believe 90% of them are Brits, Germans or Spaniards, with the odd American or Nordic.