> For example: if you saw two guys at a company booth, one guy who was slightly overweight, had a unkept beard, and wore a t-shirt that had the Perl deCSS code, and standing next to him, was someone in dockers, a button up shirt, and had a blackberry, you might make some snap assumptions.

I think the point here is that even if you (internally) make those assumptions, you shouldn't externalize them. Give everyone the benefit of the doubt, so to speak.