No matter what you all say, no matter what CIC does, there WILL always be marriage fraud. It is unfortunate but true. It is a form of crime and crime will always exist no matter what. You can only control it. Even in the US where the "Green Card" through marriage is conditional for 2 years, marriage fraud is rampant you wouldn't believe it. It even goes as far as people paying for marriages to get the green card. Trust me when I say it is rampant.
CIC is part of the problem. Did you hear the woman that said she was in Morocco 8 times?? I can assure you that the guy she was going to marry did not visit her in Canada once! CIC will never allow fiancées to visit their Canadian partners before marriage either with a regular visitors visa or with a fiancee visa like they have in the United States. The excuse is that the visiting partner will never leave Canada because he or she already has strong ties to Canada. Whereas, CIC will gladly give a PR card after marriage. Even in genuine relationships, you still need to know each other to make sure it will work.
Currently, the Canadian partner has no other way to do a due diligence on the would be husband or wife. He or she is left without a choice but to get married first and then bring the partner to Canada. It is after this that the unsuspecting partner begins to notice signs. Although this is not a fool proof way but at least you give them a chance. Furthermore, if all the foreign partner wants is to enter Canada, he or she might do that on a TEMPORARY visa and not a PR card as the system currently permits.
In my case for example, my girlfriend was refused a visa to visit me. I want to get married soon but I need to know the girl and she needs to know me... we need to spend some time together. The Canadian embassy wouldn't give her a visa. They say she wouldn't return to her home country. She has traveled out of her country before, she makes good money, she is educated... etc. Now I am forced to go and get married and bring her to Canada. God forbid we get married and we discover we are not a good fit... it becomes a case of "marriage fraud".
CIC think they are smart but I think they are stupid.