Shawn, those deer those guys are hunting must be wearing watches. Or, more likely, they're coming in to a feeder. I've never seen a free range deer come to the exact spot day after day at the same time without some outside influence. It takes very, very little to make a mature buck change it's habits. Sure you can find any extreme case to point out an abuse of anything, but the average guy isn't going to be buying 20 trail cameras.
The way I see it is that they just confirm what we already know. I mean, if you have any sense at all, you'll place it where you've already determined there is something to watch. Deer especially bucks, leave signs. Rubs, scrapes, footprints, beds, visual sightings, etc. Like TJ said, it's not like some dude just randomly straps one to any old tree, gets a picture of a deer and, a month later, can go back to that same tree and kill that deer. That's silly.