Let's combine the idea of hyper-targeted advertising based on mass data collection with custom tailored addicted substances.

If I design a chemical that will specifically make you fasterik so dependent on it that you'll do any sexually depraved things that a line up of random strangers want so that they'll give you pocket change so that you can get another hit of that chemical should it be illegal for me to surreptitiously give it to you in a product that you buy from me?

Why or why not?