Using trust like this is wrong. However, trust system is not moderated. Unfortunately, there are many people who misuse the trust system and you can even see this in the Default Trust network. The trust system is a well-intentioned idea but poorly implemented. It would actually be better for the site if it didn't exist at all. The trust system is used for many things that have nothing to do with trading. It's full of people who abuse it for their own benefit.