>It doesn't much matter if it's really true or not. The real question is whether it's plausible or not.
God lord, is that really the standard we want to use for any news source (even social news aggregation, such as Hacker News)? I may be lying but I'm lying well so that's basically as good as the truth?
Whether or not this story actually happened is irrelevant as there's nothing any of us can do to help the situation. It is however useful as a jumping off point for discussion and to come to a consensus about what we should do in a similar scenario.
Facts about this particular incident are irrelevant to a generalized discussion about police power and how we as people should respond to an irrational and/or overzealous police force. It is entirely uninteresting to discuss particular facts of an isolated incident; the real discussion comes from a generalization of the issues involved. For the purpose of initiating discussion, all that matters is that the scenario described is plausible. Of course its more than plausible, similar scenarios have played out before where well intentioned reports ended up getting investigated themselves. Discussing the pros vs cons of such a scenario do not require that the initial jumping off point be provably true.
Truth matters in discussions as well as the news. If we can't bring fact and reason to discourse, what's the point? Also, I'd hope the Hacker News community has at least a slightly higher standard for itself than 4Chan.
Ignoring the commentary on whether or not this needs to be a true story to be worth discussion, or as something to speculate on likelihood -- I've got the odd feeling that I trust the story more from 4chan than I do many "reputable" media sources today.
It seems the more mainstream media I consume, the more I notice faults in the reporting that, even where unintentional, connote bias. A simple, throwaway example from 2 minutes ago; the Grist reported on a possible fracking-induced earthquake. The earthquake was a relatively harmless 3.something, but the illustration for the photo was a large concrete wall that had been deeply cracked[1], as if to suggest that the earthquake had caused it.
In short, it's rare that I read an article from any news source without being able to point out either an inaccuracy, a vagueness or a deliberate misrepresentation of fact. That isn't to suggest that 4chan is inherently more reliable -- clearly, trolls like this happen all the time, and just for the lulz, but I don't see it as inherently less reliable a source either.