Well..I put sometimes only because I think most of us won't fit perfectly into the 3 options. When my brews are in the ferm-chamber... I don't cover, (not alot of light gets into a fridge....). But when the brews are out of the fridge, (usually to make room for another brew or to secondary in the 'man room'), I cover them always. Hell, even when I rack to secondary, keg, bottling bucket, what ever, I cover them with a shirt. Everything I've read, rather on this site or in books, have stated that light exposure to beer is bad. Thats why beer has been put in brown/green bottles for as long as beer has been bottled. So to say there is no consensus..... I think 99% of people cover their carboys when there is light exposure to worry about. Dark closet..no but lighted room like the pic posted above...a no brainer.