Flickr and Creative Commons

I’ve nev­er giv­en it much thought as I’ve tried to be con­sis­tent, but Flickr allows users to switch back and forth between Cre­ative Com­mons licens­es and tra­di­tion­al copy­right, despite this being in vio­la­tion of the CC license itself. Most of my work has been pub­lished under a Attri­bu­tion- Non­com­mer­i­cal, Share-alike CC license since I first learned about copy­left sev­er­al years ago. And though I’ve nev­er real­ly con­sid­ered degrad­ing the license back to full copy­right, appar­ent­ly oth­er peo­ple have done so. I don’t know of any legal fights over this (yet), but it seems like it would be a near­ly impos­si­ble posi­tion to defend.