Mark Cuban comes up with a very plausible analogy:
"The best analogy for traders ? They are hackers. Just as hackers search for and exploit operating system and application shortcomings, traders do the same thing. A hacker wants to jump in front of your shopping cart and grab your credit card and then sell it. A high frequency trader wants to jump in front of your trade and then sell that stock to you. A hacker will tell you that they are serving a purpose by identifying the weak links in your system. A trader will tell you they deserve the pennies they are making on the trade because they provide liquidity to the market. (From Wall Street Insider)The Sunday New York Times today suggests a similar conclusion but not the perfect analogy:
“The financial industry always finds ways to stay ahead of the
regulators,” says Kenneth S. Rogoff, a former chief economist at the International Monetary Fund and now a professor at Harvard.
“Whatever law they design today, if it’s not updated in 15 or so years,
it will be completely ineffective, completely irrelevant.” (From New York Times: Rule 1 - Make Money by Avoiding the Rules")