Just dont have anything in the pic that you would not want anyone else to see. And nothing in the pic that directly ties the evidence to you, or at least make it obvious.
one of the reasons the pics we post automatically become property of RIU is so that we don't get connected to it. but like the prev post said just use your head and don't post pics of you smiling holding your driver's licence giving a thumbs up in your garden, unless you have a MM card and can do that.......what a goal.