Actually we do collect PINs for PRC Unionpay cardholders. Although Unionpay is progressively moving to chip (their chip - "PBOC 2.0" not EMV), the majority of the cards I see brought down from the Mainland are swipe cards and the verification convention is to require both a PIN and signature.

But I don't see this being done for Visa or Mastercard cardholders from overseas. Even oreck, who used a RBC card to pay at Rainbow.