If it’s a stupid post, which is more or less just a troll/flamebait? Delete key!

Uninformed, passionate post which is wrong? Calm responses, show that everyone on each side of the conversation is human; and… then the Delete key!

I do agree that you need a way to show an outsider that they are arguing with the creator of PHP about how feature X works, or other similar scenarios. But I don’t think baking that into a tool in a manner similar to a spam filter would be healthy.

Case in point:
Shelley Powers vs HTML5 / Ian Hickson – Microformats and data.

Ian is a huge controlling aspect to what gets put into the HTML5 spec, as he’s the one with his fingers on the keyboard.

Shelley is an advocate for RDF / RDFa. RDFa is a standard for microformats in XHTML, so not unreasonably, she (and many, many others) suggested its use in HTML5.

This situation devolves pretty quickly. Ian appears closed on the idea of RDFa; but after much back and forth a new section appears in the spec. It’s not microformats, it’s not RDFa. All efforts to suggest that this is wheel reinvention seem to be ignored.

If Shelley’s ability to provide criticism in the same venue as others was restricted by karma as you described above, much of the community around HTML5 would be unaware of this issue.

Because of the tension between her and some of the core contributors, she’d be out on her behind in an instant. The issue would never have escalated, and I’d be unaware of it; I’d have no chance to contribute to HTML5 / use cases for RDFa.

In these situations, I don’t think you need tools to manage noise.

You need people to manage people (sooth, clarify, cajole), clear rules (don’t X, Y, and show a little respect!), and a way to get rid of the annoyance that is less costly that creating the annoyance (delete key).

Putting the threshold to -2 instead of -1 would make more sense, but I still don’t think it would be a good idea. Not from a social view, and also technically it would be.. say, interesting, to implement that given the frequent switches between your L2 and L3.

New people would be highly discouraged as well if they can’t make the jump from L4 to L3/L2 – and I’m not only talking about internals (what you maybe had in mind as well) – I’m only a reader there, sitting on L3 myself, but I have the feeling the “bogus” +1/-1 votes are easily discarded by the decision makers and I don’t think there’s much noise to begin with.

For somebody with a “maintainer” role it might be important to get all reports about possible problems – independently who the sender is. Some distributor might only be interested in bigger decisions and focus on “the big names”, some lurker might be interested in some of the big stuff, that is not too technical, and in some beginner questions where he can (finally) answer. Just to name a few ones.

Of course there are uninteresting things, but every modern mail client should be able to create filters to ignore specific threads and/or persons and highlight others and on that list it’s not like there was such a fluctuation on the list that you can’t recognize names and decide yourself.

Oh and with your approach there’s the problem that internals handles quite some “special interest” stuff – like a patch to some “less important” extension, that might be send by a “L5″ and not be interesting for anybody but the “L1″ who is maintainer of that code.

I certainly don’t like anybody else to decide which mails I get to read.