If you have a specific target audience, you don't want to attract people that might waste your time. If you happen to be in the scamming business, you almost certainly use methods to filter out any reasonably competent people.
You'd have an arsenal of tricks such as using low resolution images, incorporating grammer errors, sprinkling in a few typos, and using weird fonts.
This way, there's a much higher chance that the person that responded is one that is ..... enough to fall for your schemes.