Merit sales, transfers to aliases, back-and-forth trading, etc. are not much of an issue. All illegitimate merit will decay, and will account for a tiny and very expensive fraction of the total merit economy. It's basically a rounding error; fight it where convenient, but waste no sleep over it.
That is what theymos said on merit trading.
DT Members- they are not allowed to red tag those who are trading and exchanging their merit as what The Pharmacist said.
I would gladly tag merit abusers, but as I've said before it appears Theymos doesn't want that, and I have to respect his stance. Also, these cases of abuse are much less clear to me than account sales or even campaign cheating. There definitely can be users who really like what one particular person has to say, and I might tag such a person unnecessarily. I don't feel like dealing with the backlash of that, nor do I really want to neg someone and be totally wrong.
This all will take care of itself eventually; I have some faith that this'll be true. We're only in month 2 of the merit system, so it's still young. It wasn't designed to stamp out shitposters immediately--it's a gradual, long-term thing I think. We'll see in a year or two.