Saturday Night in a Duty Free shop I tried to purchase a simple bar of chocolate. Fine I Knew that I had to produce my boarding pass but then I was asked to produce my Passport. I refused to hand over my passport to a shop assistant and was told that they could not sell me the chocolate. Is this a new demand from King Power and a route to gathering information?  

I think it is Thai customs that requires that information. It isn't a new that Kingpower need passenger details as well as flight number but in the old days they would manually type that information from the boarding pass but nowadays they simply scan the passport.

Scanning your boarding pass in Duty Free shops worldwide is just a way for the retailer to get tax breaks. Scanning passports is a whole different issue. A Passport is an extremely important document containing very personal information, not something to be passed around. 

Nothing new here.  Always have to show passport and boarding pass to buy anything in duty free
This has been in place for a LONG time

On 1/22/2018 at 7:59 PM, seanog said:

A Passport is an extremely important document containing very personal information, not something to be passed around. 

Try telling that to banks, hospitals, post offices, etc, etc here in LOS as well as to duty-free shops at BKK.