"They are not prejudices just being honestly wise.
You would be perfectly ail right about things if you happened to see someone posing with a gun in your local park, or saw someone shifty coming towards you on a dark night would you?"
No, the one thing they are not is being honestly wise, but hey, if thats the way you wish to rationalise your prejudice, that's up to you.
And there is a massive, huge difference between a photo of a man posing with an assault rifle over in India and the notion of seeing someone in a local park posing with an assault rifle. And someone shifty? Is this guy "shifty" then? Just on the strength of a photo?