My experience is not in Canada, so I can't answer for the CRA. I can answer in the U.K. context, and some other European country contexts, which I know.
I would certainly say my experience here is that they're doing exactly as you've described. There is a much higher probability of being audited and investigated if you're a small company rather than a large company. We have a history in the U.K. of making what appear to be somewhat cozy deals with large companies, perhaps the exception, curiously, being GlaxoSmithKline, but by and large, we have had a history that has given rise to a lot of public anger.
We've had our House of Commons holding a lot of hearings into companies such as Google, Amazon, and Starbucks, despite which, and despite everything that is being said about the G-8, nothing they have done, which has given rise to a lot of public anger, will be anywhere touched by the arrangements on tax avoidance that I believe are being brought forward by our U.K. government. To get this right, we're dependent upon changing the rules on things like “permanent establishment”, which is a concept within the OECD double tax agreement. That has been heavily abused.
I discuss this extensively, by the way, in a book that you can get on Monday. It will be published by then. This is an ongoing issue that we really need to address.