Spammers are not so harmful and they can be detected rather quickly and deleted. Their principles are not built on deception like the other two.
C..nts are bad because they can be damaging to a person's repetition, especially if that person is not a WG. However, they can be caught out with a bit of detective work. For example, visiting other forums.
Writers are also bad as they give a false impression. However, their actions are not harmful to the pro, though it is still inethical. The biggest drawback is that they are the hardest to detect as the writer knows everything there is to know about the girl.
Overall, I would have to say the c..unts.
