The Government of Canada released a proposal and consultation last week that targets three tax planning strategies, that in their view use private corporations to gain unfair tax advantages for high-income individuals. The strategies targeted by the proposal include income sprinkling, holding a passive investment portfolio inside a private corporation, and the use of capital gains to gain a lower tax rate.
The proposed legislation is complex, however you can check out this publication by PWC, which provides a great summary.
Link: Government targets tax planning using private corporations