I have flown Qatar on the following routes:
DAC - LGW (business
GVA - DAC (business)
DAC - IAD - DAC (economy)
Security was ver rudimentary at DOH, except for my flight to IAD. In Jan 2004 I flew Malaysia from KUL to EWR and we had to deboard DXB. Extra security checks in KUL and DXB (both locations were supervised an American official)
Did not notice this when flying BA to Washington via LHR.