If you want an exchange with a Tobin Tax, then create one. Everyone who thinks it's a good idea will trade on it. Others won't unless you force them to. We'll then let people figure out how valuable HFT is.
Ugh. This isn't how laws work. I'm not suggesting it nicely and asking 'pretty please'. Government should, can and has been used to promote justice, equality and fairness. But only if people care to use it to do so. Trying to do everything outside of the system will result in failure. Nobody here has given me any rational reason as to why HFT is a good or moral or productive or beneficial thing. Therefore it should be stopped. This attitude of "I'm taking my toys and going home" does nobody any good, including yourself.
The way I look at it, natural law's point is a valid one. Go start your own bourse.
People cannot give a rational reason for every little perk in a corporate list of perks, but what they can ensure is that with a good possibility of takeovers, the perks remain at around the right level, neither too high nor too low. The way I look at it, if HFT is that harmful, then conservative business owners would float their shares in "slower" exchanges.
This is the bitcoin world. People don't complain. They compete.