Really, there is nothing wrong with securing your borders. Canada is protected due to its geography (pretty hard for people to sneak in across the oceans or from the US), so doesn't have this problem to any great extent. 

Still, Canada has to watch very carefully who we let legally into the country. To argue otherwise is foolish. CSIS should have more of a final say in vetting potential immigrants, and not be overruled by naive politicians, as is frequently the case.