Rumor has it that Apple may be preparing image surveillance into iOS.
I have no idea the validity of this claim, but holy cow is it a bad idea to go down such a road.
And before you say, "Well, if you're not doing anything wrong …" give it a rest. Define "wrong" in this! And, once an organization has such tools in place, "wrong" can be updated on a whim. Next, it's, "Oh, we see you have pictures of X, or Y, or Z on your phone. Well, we can't permit that." And, next thing you know, the cops are at your door because you have a picture, or a book, or a controversial thesis, or whatever.
This would be incredibly bad, and should it come to pass it will be a deal-breaker for me and the iPhone.
Let's hope it's just random speculation.