I bet Google "could" write some algorithms that can predict if a stock will go up or down seconds before change based on live search data. All it takes is for an article or something to come out, then watch people search for "Will IBM stock drop" - and perform live sentiment analysis across all such live queries involving the stock name.
In a sense, it's all about what information you have access to.
So the rumor is Goldman Sachs got out of the financial crash first because their systems saw the market move before anyone else. I don't know if that is apocrypha, but it is more to the point Google would not be predicting the market, but instead see market movements before anyone else.
I highly doubt that it is as technical as you seem to make it.
GS is very well connected, and they are constantly out there asking people for their opinions. Ten years ago they probably had some sort of database where people could share experiences, and that is most likely what led to them guessing the financial crash.
But it's not like they had some machine that one day told them to short mortgages.
I checked you bio are developing your own HFT strats? I ask because I am connected with a couple startup HFs. Ping me on Symphony {Brian Hewes} if your up for chatting about it.
In a sense, it's all about what information you have access to.