You can buy heroin everywhere. It's his job, as a father, to educate his son about drugs and other addictive substances. Blaming Silk Road is lying to yourself, but some people lack autocriticism and like blaming other people. In fact, I bet what they sold on Silk Road was of higher quality than what they sell on the streets.
The more I read about the war on drugs, the sadder I become. I used to be one of those that wanted to leave everything as it is today, and I've changed my mind.