Many of them, immigrants, get money from foreign sources or numbered companies. 
You are so oblivious about the current situation.    I hope the government is not as naive as you are.

Also, many of them homes are to be flipped within a year.  So renting out is not an option for many investors.
You would think this only happens in Vancouver or Burnaby.  No, Maple Ridge, Mission, Chilliwack, Langley etc.