"the machines just took over"

Not The Matrix, but Wall Street.  How comforting. 

"Fat finger" error or otherwise, it seems ironic that electronic trading systems designed to buffer against volatility would themselves contribute heavily to the largest point swing of volatility in the history of the New York Stock Exchange.

"You can't have the U.S. stock market have this happen to it," Saluzzi says, adding that regulators need to examine this closely. "The SEC just got something new to look at," he says. "Regardless of the cause, the bottom line is that the system failed. This could happen again."