I think it's unwise to underestimate your fellow humans' propensity to "be a dick", as you put it, even if they don't gain anything more than the satisfaction of treating others poorly.
Facial recognition + a database allows POWERFUL and fine grained discrimination!
Imagine being able to know ${Things} about people -- via analytics / The Internet -- whenever any prospective customer comes into your store.
You could refuse to do business with gay people, divorcees, adulterers, married people, transgender people, politicians, members of the opposing political party or religion, or even police officers with X number of complaints. You could exclude people from the wrong side of town, or who didn't go to the right schools, or whose parents were (or who themselves are) illegal immigrants.
Many of these things are Probably Legal (some are likely not), but most of them strike me as unjust treatment of others. The technology allows frightening things, and there are MANY people who would do so right now if given the ability. (Religious and political boundaries are one such place where people are quite willing to do so.)
I only touched on business owners. Now imagine that roving bands of jerks (or criminals) got their hands on the same technology or data, and could tell who was a stranger in town, or was more vulnerable than others, or fit their desired target criteria. It's pretty scary, and I'm sure that within ten years we'll hear stories of such abuse happening.