Trading methods/practices not available today?

Recently I saw the SEC ban pending for Flash trading, and I wonder if there has been other "exotic" trading methods in the past that are now long gone and probably wont be reintroduced due to their exploitational factor.

I looked up on google but found nothing other than pure scams.

I was wondering if there was a certain way to trade the public markets at some point that we do not have access to anymore.

well options used to have loads of little cheats and niggles you could explout back in the pits in the 70s and 80s

Locals still front run big orders in the pits by reading whats being signalled
from the broker phone booth to the pit trader executing the order.

Makes them some good money.

Yeah but I was thinking more in the terms of banned practices and not regular scams