Half a million-one million illegal in Guangzhou(no exact figure).china has 1,4b people.
5,000 / 1,400,000,000 = 0.00000357142 or 0.0004%
even if 5,000 aliens are all vietnamese, the figure is still almost 0.
We got to nip it in the bud and Germany and many other countries have taught us a lesson.