CRA should go after Canadians stash of money in tax havens, and push for a global shut off of the banks  and economies of these jurisdictions. This would involve co-operation of many countries. There is a thriving underground economy, but it involves more resources to go after the "higher fruit". Unfortunately "lower fruit" is always easier to go after with less resources. Just find a few T5 or T5008 slips that have to be reported and tax them higher.  That's an easy desk review.