Is it legal for a forum administrator to read users private messages?

I live in Canada and I am the administrator of vBulletin community forum.

I would like to protect my forum and members if I suspect harassment or illegal activity.

Is it legal to read members private messages?

I heard that for example in France, the article 226-15 from Penal code and article 9 from Civil code doesn't authorize forum administrators/ moderators to see private correspondences between users. Even if they discuss about harassment or illegal activity.

Thank you for any advice !!

[sandra]

In the United States law gives specific exceptions on when private communications can be intercepted and reviewed. The basics of which can be read here:

United States Internet Privacy Law Summary and Law Digest

Of course, the administrator can simply rename Private Messaging and disclose in their terms of service that it is subject to review. Than the user doesn't have any expectation of privacy using the service.