According to wikipedia [1], 70% of the products sold on silk road were drugs

https://en.wikipedia.org/wiki/Silk_Road_(marketplace). wikipedia uses as reference https://web.archive.org/web/20160407165324/http://gawker.com... and https://web.archive.org/web/20131012012106/http://www.thegua...

plus, at least ebay, amazon, big tech comply or at least sometimes comply with the law banning some products which can't be sold or advertised