That thread on /ck/ was legendary! I've also seen some pretty funny "ITT: Pretend we're HN" threads on /g/. The Overlap between 4chan and HN seems to be larger than it originally appears...
I'd be suprised if most people on 4chan's /g/ and other anonymous technology boards wouldn't frequent hacker news on a regular basis. The individuals behaviour just depends on the sites social norms, so they're not a nuisance here.