Stock exchanges could limit program trades... By requiring traders to enter a character sequence displayed in an image, as Google does when creating new accounts. Of course big financial institutions could afford hiring people to monitor the markets, and enter codes 24/7.
Why would they do that? So they could lose 50% of their fees from the million computers trading? Insane idea.
Just what society needs .More verificationism. Next we'll have to imput capchas for access to such essentials as air.