There is a theory (which I believe is yet to be tested) that if you pass a by-law saying that owners accept that they will be fined for illegal parking, then the can be fined. The same theory applies to 'management fees' for issuing Notices To Comply.
Given that you need 75 percent of those voting at a general meeting to pass by-laws, this is not something that can be imposed on the whim of a few individuals. Whether or not it's legal or not is another issue but from what I hear, it works as a deterrent so where's the harm?