Now that I think about it. The only site I've had anyone say anything,....was this.
On other sites, nobody would have the chance to say anything in the first place, because the whole thread would likely disappeared. Of course, with "other sites" I mean support sites, not general flight sim sites.
I guarantee if you post non-Orbx screen shots in their forum it will be deleted faster than you can blink an eye, Not sure they will ban you, but you will probably get a warning PM from the Admins.
Personally, i've never thought it was in good form to post about competitors products in another developers forum. Besides ORBX, I wouldnt post screen shots or videos of FlyTampa, Aerosoft, or any other developers airports or sceneries in Umbertos forum and wouldn't do it to the other developers either.
Sure its fine to do at Avsim or other non-developer forums, but doesn't seem like a good thing to do at a devs site.