Sorry. MA misunderstands the term 'sharing economy'. Look at his examples: accommodation sharing (e.g., AirBnB), ride sharing (e.g., Uber), music and video streaming (e.g., Spotify), online staffing (e.g., Fiverr), and peer/crowd funding (e.g., Kickstarter). None of these are namby-pamby unrenumerated sharing -- they are all strictly for-profit industries. Their common denominator is that they disintermediate gatekeepers to these industries -- hotel chains, taxi companies, record companies, employers, wall street, respectively -- by creating venues where producers and consumers can find each other (with reputation attached) through an inexpensive interface.

Looks like Canada is just trying to tax this direct income. While I'll pass on a discussion on the legitimacy of income tax in general at this juncture, if they have a legitimate power to tax traditional employment income, why would they not have a legitimate power to charge direct producer-to-consumer income?