Possibly some people have been exposed to mircea through hearing about his insane quotes such as:

  The most you can do, after having been educated/raped, is picking the what and the how for other, later, virgins.

http://trilema.com/2014/patriarchy-is-a-thing-because-nobody...

Or they have read his Guide To Beating Women blog post:

http://trilema.com/2011/cum-se-bate-femeia/

Or perhaps they have read how his site for betting with bitcoin screwed someone over for about $7,000 in bitcoin:

https://bitcointalk.org/index.php?topic=339544.0

Do we know how much he's actually worth?

His >50% MPOE[1] stake is at least 1.4 million coins (valuated by the last trade).

If you're skeptical of numbers on webpages (c.f. "EmptyGox"), MPEx's trivially traceable addresses[2] currently contain around five thousand coins; tracking down the rest is left as an exercise for the skeptical sleth.

[1] http://mpex.ws/?mpsic=S.MPOE

[2] https://www.walletexplorer.com/wallet/MPEx.co

Maybe I'm reading it wrong but according to that there is ~10m shares outstanding at a price of 0.00028btc per share. Doesn't that make it worth around 2800 btc not 2.8m?

We're both wrong. One billion shares, half of which he can't sell:

  CL-USER> (* 1/2 (expt 10 9)
              (parse-float "0.00029087" :type 'rational))
  145435

Oh, and who the hell is paying 50 btc to open an account at mpex?