"an organization may disclose personal information without the knowledge or consent of the individual... if the disclosure is made to another organization and is reasonable for the purposes of investigating a breach of an agreement or a contravention of the laws of Canada or a province that has been, is being or is about to be committed and it is reasonable to expect that disclosure with the knowledge or consent of the individual would compromise the investigation;
So, yes, if you can convince an ISP that the information is for an investigation (not necessarily a police investigation, a private eye or corporate audit would suffice) then yes the ISP can give out your private information.
I especially like this nugget:
"reasonable grounds to believe that the information relates to a contravention of the laws of Canada, a province or a foreign jurisdiction that has been, is being or is about to be committed"
So, personal information can be disclosed even if I am about to commit a crime in another country, e.g. I surf a beauty pageant website and view the enter pageant page that is hosted in Nigeria (beauty contests are illegal under Sharia law).
Sigh, well done Canada. Well done.