I hope you understand that the thievery has been happening for centuries, millennia. There is no other way to gauge real supply and demand than to put buy and sell orders into the market yourself. HFT is doing at ultra-high speed what human market makers do all day long, and have been doing forever.

Now, possibly rightly, market makers in general, through the ages, have had a bad rap. They are indeed trying to get more information than the average joe, with very clever, and risky, techniques (see below) and skimming him after having done so. Nevertheless, you must remember, that without these people/machines taking these risks, you would not have a continuous market in which to trade. You'd have a much more stepwise price action and much more risk. They're providing s service.

Perhaps most controversially, being a good market maker means having some capital, so that you can wear a loss which is entirely possible during your price discovery. Thus, market makers who make money, inevitably already have money. This doesn't help their cause.

But the idea that HFT per se is the problem is wrong. If you don't like HFT, you don't like finance, period. That may be a legitimate view, or not, but the two are inextricable. They are not different one from the other - HFT is simply Amazon doing what Barnes and Noble does, more efficiently (without the monopoly aspects - HFT is fiercely competitive).

Without HFT, bid offers would be wider. Fact.