I know Jeff Atwood and Joel Spolsky are the owners or creators because I came by the site from reading their blogs.
Who else works for Stack OverFlow in here?
Does Jon Skeet? There's also a fair number of 100k+ users now.
The answers from them are quite informative. It seems that to get that many points in such a short amount of time (the site's only been online for 2-3 years? ), you would need to be spending quite a lot of time, regularly on here, so either they
Have a ton of spare time either at work or outside of work
Are unemployed (seems unlikely given their breadth of knowledge)
Work for Stack OverFlow and their job is partially to post answers.
These guys seem too knowledgeable so reason 1 or reason 2 seem unlikely, so I suspect reason 3.