Manipulation in prediction market for president

Over the past month irregularities in the InTrade prediction market for president have been reported on by multiple sources. As far as I know it was first written about by Nate Silver on September 24 at FiveThirtyEight.com (if you've never been there before here's fair warning that it's pretty addictive), here:

Intrade Betting is Suspicious by Nate Silver

Well these suspicions have now been confirmed by InTrade CEO John Delaney:

Price Variances on Intrade Political Markets by John Delaney

From the message:

The trading that occurred during these times may be summarised as follows...

1. Multiple large volume Buy orders placed and matched rapidly caused the McCain market to move significantly above the previously prevailing market price by up to 10 pts.
2. Multiple large volume Sell orders placed and matched rapidly caused the Obama market to move significantly below the previously prevailing market price by up to 9 pts.
3. The market prices of the contracts then seemed to represent discrepancies between overlapping Intrade markets, and also between Intrade markets and similar markets on other platforms for some time thereafter.

Interesting stuff, but in hindsight not all that surprising. I'm just glad that no one in the media was naive enough to report the manipulated numbers as meaningful.

Oh, wait.