HN as a credible source in Wikipedia?

As evanrmurphy says, the citation is only there to link to the relevant HN thread; it's not implying that HN is (or isn't) a credible or reliable source. There's currently 57 external links to HN from the en.wikipedia.org domain,[1] though not of all them are used as citations.

Wikipedia's Verifiability policy indirectly comments on sites like HN here: http://en.wikipedia.org/wiki/Wikipedia:SPS#Self-published_so... (and the section directly below, "Self-published or questionable sources as sources on themselves"). So for example, a comment pg made on HN would be something that would be an acceptable citation since his work in the field has been published in numerous reliable sources in the past.

[1]: http://en.wikipedia.org/w/index.php?title=Special:LinkSearch...

That citation is confirming their claim from the first sentence of http://en.wikipedia.org/wiki/Zynga#Intellectual_property that Zynga was indeed criticized on Hacker News.

I'm not sure that's the same as calling HN a credible source, because they're not vouching for anything said here. In any case, it's interesting and I've never seen it before on Wikipedia. :)