I subscribed to this guy's high frequency trading programming blog, but I have only mild curiosity about how it works.  Imagine that you did succeed in writing software that could purchase a security 10 microseconds before another guy: the time spent writing software to shave off microseconds could have gone to creating something beautiful or useful or entertaining for people.  And if the purpose of trading securities is to allocate capital to companies that make stuff society wants, it's hard to argue that a company would be harmed by getting its money 10 microseconds later.