Hmm, I didn't interpret the author's quoted words as meaning that any transaction outside of full-time employment or business is illegal. I thought he was just alluding to the common argument that has been used in lawsuits against Lyft and Uber. The argument goes that Lyft and Uber are transport providers and hence must operate under existing laws - for instance, obtaining transport provider licenses, accepting liabilities for accidents, and treating drivers as employees. Lyft and Uber instead say that they are a technology company and don't need to. It's a subtly different argument. I do wish the author had presented the argument explicitly, though.