When I was in PFG Marketer Services I saw million dollar double payout fuckups all the time and a shady SQL Server database for "manual over-rides" on commissions to brokers that seemed like an un-audited slush fund.
Most corruption happens in a matter-of-fact, business-as-usual, we're-all-in-this-together atmosphere. And the proceeds don't usually lead to blowout lifestyle extravaganzas, as most participants are clever enough to realize that draws unwanted scrutiny. That is what makes corruption so insidious and difficult to root out. The rot spreads slowly, and inspection is commonly asymmetrically more difficult and costly to mount than undertaking the corruption act itself.
The most reliable way of rooting out corruption I've seen is an organizational culture that nurtures trust between leadership and organizational members, equitable gains sharing (so members feel they have skin in the game), and fiercely protecting whistleblowers (where the vast majority of human organizations utterly fail). Personally, Dunbar's Number appears to be some kind of (hopefully) local optimum but I'm curious how Geoffrey West's findings of scaling square with corruption incidence and scale.
Well for me, it's taking information flow off of the table. Not having access to the trade at execution (and how long it was an order) puts me at a disadvantage. I'd take the market impacts to have greater transparency.