There's a well known technique used by cops (relayed to me by a handful of retired NYC cops that worked security at a former job): you let the small time offenders go, so that they are more willing to help you with the big problems down the line.

One cop explained it like this: "We'd find guys smoking dope on their stoop, say hello, and just keep walking," he told me. "But we'd remember their names and faces. Then, when there was a murder or rape in the neighborhood, we would drive around, pick them up, and say 'Remember when you were smoking dope and we didn't say anything? Well, now we need you to repay the favor. Give me some names...'"

In one sense, it was a way to coerce inside intelligence contacts. In another sense, it was cops recognizing that in a city like NYC, there are bigger problems than someone smoking pot on their doorstep.

Now the internet is the city, and these cops are arresting every jaywalker and litterer they can find. Somehow, I doubt it will turn out well in the long run...