While I agree with the initial post that HFT is basically skimming, front running, and market manipulation, I have to disagree with the original poster when he says the stock market is like a casino. Long term, the course of the market is set by investors, not day traders and HFTs. Sure, they can manipulate the market a bit day to day, and even apparently cause a "flash crash", but if you are in the market long term, and an actual investor, as the stock market was intended to be used, the HTFs will have little affect on your returns. If you buy and sell once or twice a quarter, like I do, they may get me for a couple cents a year, but they are not having any real affect on my investment returns. I'm paying way more in ETF fees that HFTs are getting from me.
As for slowing them down, I heard someone propose a rule that you have to hold any stock you purchase for some set amount of time, like an hour, or a day. It's not a radical idea. The IRS actually has a "free ride" rule, where if I sell, then buy a different stock the same day, with the same cash, then I have to hold that stock past the settlement period ... about 3 days ... before I can sell it again. That rule does not apply to margin accounts, so HFTs avoid that rule by setting their accounts up as margin accounts (even if they don't use margin). So, make the "free ride" rule apply to margin accounts, problem solved....