One of my great arguments Rick as I always believed that was not the case.
According to law here you must carry your official identification on you and for most of us that is a passport.
You need it to check into a hotel and if you are doing anything else commercial like changing money at the bank. I have been asked twice on the street in the Sukhumvit area for my passport and I have heard recently people are being asked to produce their passport upon demand in Pattaya also.
Is it law??????????? I am not sure and that is why I am asking the learned here. I have been told carry it to be safe.