Meth. Or Anthrax!
Or you could SEARCH as this question has been asked a million times before, and the best answer is to NOT RIP PEOPLE OFF! If you sell your shit un-cut, in the long run it WILL PAY OFF!
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"I am not one of those weak-spirited, sappy Americans who want to be liked by all the people around them. I don't care if people hate my guts; I assume most of them do. The important question is: 'What are they in a position to do about it?'" (William S. Burroughs)