Hi. I developed the website. I had the idea on the 19th of this month, then registered and developed the website on the 20th in an hour or so. Yes, it can be spammed with unreal values, but right now the values getting in seem quite real and the more people use it, the more accurate it gets. The spammers values are easily discarded based on weighted averages and if they differ too much they are not considered. At the end the user btc/usd average amount should be quite accurate.

edit: just to specify, I didn't planned that mtgox would halt trading and delete the website. It was meant to see out of curiosity how much is blocked in there with the withdrawals not being processed and fiat withdrawals taking months.