I think trail cameras are a great tool to use when used correctly. I think a lot of hunters can't fight the urge to check their camera and fill the area full of scent they also put it over a bait site and not on trails leading to bedding areas or food. I use trail camera's not just to see what maturity of deer I have but what direction they are coming from and when they are coming.
I buy into this.
What I see a LOT if is guys putting them in areas that are likely holding good deer.....and checking them WAY too often. How much is "too often"? How much would you HUNT a good spot? A deer doesn't know the difference in whether you'r escouting, hunting, etc... he just knows you've been in his house, AGAIN. That's pressure. I just prefer, now, not to pressure them any more than I do when I'm actually hunting them.
I put up my camera over a mineral site for about 3 weeks, last season. I'm not sure I'll use it at all, next year. I've taken two bucks I had trail cam pics of.....and that was a cool experience. But I'm not willing to take that chance, now.