>Just because a system isn't foolproof, doesn't mean it's useless.

I think this is... a common mistake people make. It's a common mistake I make, really, to look at a system for preventing a bad thing, see a hole, and then argue that system is worthless.

All systems have holes, and just 'cause a system has a hole you can see, that doesn't mean the system doesn't have value.A system that prevents 80% of the bad things it was designed to prevent can be really useful.