In december 2011 I saw 3 transactions on http://www.bitcoinmonitor.com/, over 3 days, just around 500K BTC each.

This means:
- that at least one single person sits on 6-7% of the total amount of Bitcoins out there - probably even more.
- In relation to the marked depth last 24 hours, it is total control

 
Any comments on this?


As a sidenote:
You really have to trust the "system" to transfer that many "money" in one single transaction.