I usually release all my fish, pictures or not. Once in a while I'll keep a trout to enjoy, but for the most part, I send'em home.
I wanna play devils advocate here just for a second.
What is the inherent difference between keeping a very large fish and harvesting a "mature" buck? Just like a large buck, an old mature fish is more suseptable to predation, illness, and natural death....isn't it? Why would it be so wrong to take that fish home and mount it or put it on the grill, just like we hang that 12 pointer on the wall and chow down them tenderloins.
Don't we use that same mentality when we go into the woods looking for the old buck with the thick antlers? Why shouldn't we let him walk just because he's old and has weathered the storm?
Just playing devils advocate here....