[Mz]

They have quite high karma (as in "they are on the leader board") but their profile states nothing about them. I was assuming you knew something about them from their comment history. (I am sort of guessing they either were funded by YC or applied and got rejected or some such, but I don't really feel like doing some massive search of the site or combing through all their comments/posts to confirm my hunch.)

[thaumaturgy]

They have 919 submissions, the top 142 of which have between 11 and 252 points. They only have 206 comments by comparison; their second-highest-rated comment was a direct link to a pdf of Hacker Monthly #2.

[helwr]

HN search is a bit out of sync, e.g. see the top result here: http://www.hnsearch.com/search#request/all&q=by%3Ahelwr+...

and the actual link: http://news.ycombinator.com/item?id=2403290