law: 495. Prohibition against obstruction of Mayor or any municipal authority, etc.
  No person shall obstruct or molest the Corporation or any municipal authority, the Mayor or the Deputy Mayor, any councillor or aldermen or any person employed by the Corporation or any person with whom the Commissioner has entered into a contract on behalf of the Corporation, in the performance of their duty or of anything which they are empowered or required to do by virtue or in consequence of any provision of this Act or of any rule, regulation or bye-law made thereunder.