There are two completely different sets of people involved, and NO response at all is best in both cases.
Those who are out to cause mischief get a kick from any response at all...they have got a reaction, so DON'T feed them.
The others, the drug and porn people...well, 1% is a heck of a lot given the number of people/message boards they contact (remember it costs them notthing). Just 1 single sale justifies their time, and, if they are financial scammers (doesn't that job with Athens whatever sound like a dream??) 1 mug can make them more than we earn in a year.
So...Don't post on their threads...leave it to the moderators to have the fun of obliterating them!