Separate question regarding my HKG-EWR segment.

Upon boarding my flight, I saw two tabletops and 4 security personal who seemed to be randomly searching passengers on the gangway right before you step foot on the plane. Perhaps I did not notice it on my outbound segment from EWR but is this common? Is it an HKG airport precaution or a CO precaution? Is it random? I was waved on through. Just curious.