I wouldn't say that it's designed for when police don't want to do their job. There are many communities where there aren't enough police to do a good job. Using techniques like this seems like it would allow them to use actual humans where they're more needed.
The cases cited in the article were of neighbors asking the police to somehow combat the unruly elements in their communities. It seems like you're under the impression that this is a matter of "nervous prejudices" running wild, like some Salem witch trials scenario. But what would you, personally, think would be the best course of action if one of your neighbors (not you yourself) was a drug dealer whose activities were a constant nuisance, if not a threat to your well being? What would have the police do if they had tried every other tactic at their disposal? I don't know if you have children, but if you did - would you just stoically endure, put them in danger, on the basis that a technique which works might one day be abused?
I know it's lame to say "think of the children!", but when you're talking about drug dealers and the kind of trouble they bring I think it's appropriate. In high school I worked with a lot of kids from bad neighborhoods and saw the effects of living in an unstable environment. If something like this helps out kids like them, I'm all for it.
/rambling