Nothing good comes out of looking at the bad in everything because there is bad in everything. You minimize it but you will never completely control it.
If someone besmirches their name and reputation. You 1 let them know up front if they do it they wont be doing it again and you 2 handle it like you promised and you 3 dont cave in to negativity cause someone is afraid someone will spoil it. You spoil it for the spoilers and send them packing.
The idea that someone would line up 6 or 7 matches and get everyone to let them win ridiculously so they could win a $100 or so to me is just kind of laughable. Sure its a possibility so what do we do?
Do we get babysitters for grown men in the form of referees for a tournament that is supposed to be designed for goodwill and make a place some money? I dont think so what we end up doing is ........Nothing.....and Nothing gets done cause someone is afraid of their shadow.
Sorry but that's no way to live. Deal with the Dumbass that is brave enough to cheat, don't befriend people who cheat, but for certain don't fear people who cheat because they cheat themselves out of the joy of living, but they are not taking mine!
This way of thinking may work for "how to live" or how you choose your friends, but it doesn't apply to choosing a tournament format.
The analogy of locking your door is about keeping honest people honest. Sure if someone wants to get in your house, a locked door isn't going to prevent that. They will find some way to get in.
Keeping your door unlocked is the same thing as not having any rules, or choosing a flawed tournament format. You are inviting people to cheat, and people that wouldn't normally cheat may do so if other people are doing it, and it is so easy.
This is why you need rules in place, and a good tournament format, so that you don't have to worry about the bad things as much. A lot of good comes out of looking at the bad, when making rules and organizing events.
EDIT:
It's not just about the one situation the other poster brought up. I made an entire post about it earlier. Also, if you think people won't try to take advantage of the tournament because it's not that much money, you clearly haven't been to enough weekly 10$ tournaments. People are willing to cheat for a nickel, just to have an edge over everyone else.
Everything you guys are saying makes complete sense if you were holding a private tournament, with just friends. Otherwise, you need to have rules and put time in to creating a fair tournament format.