[throwaway13qf85]

Front-running[0] is where a stockbroker abuses the relationship they have with a client to place their own order in front of a client's order, because they know that the client's order will move the market, and that subsequently they'll be able to close their own position at a profit.

Having a speed advantage over other market participants and using that advantage to pull your quotes on another exchange is not front-running! It's just sensible market-making, of the kind that has been doing on for hundreds of years. It's no better or worse than sending a pigeon over the English Channel in 1815[1], or using the Transatlantic Telegraph to outpace ships in 1866.

Also, shouting "straw man" is not actually an argument.

[0] http://en.wiktionary.org/wiki/front_running#English

[1] http://en.wikipedia.org/wiki/Nathan_Mayer_Rothschild#Legend

[001sky]

Front running is a conceptual variation of the hold-up problem. Like any concept, it can be implemented in plain-vanilla as well as syngthetic variants. Non-vanilla is not dispositive.