Used T4 for DL LAX departure with onward int'l flight. I am writing to alert people to a strange potentially alarming experience at security for the B gates in mid-July. I put my shoes coat bag of toiletries laptop and other items in the trays along with my carry-on bag. In the time it took me to turn around wait for one person ahead of me to walk through the scanner and reach my trays (20 seconds) my laptop had disappeared. I had read about this sort of thing before but thought I had taken the right precautions. No amount of asking staff to help got me anywhere other than a warning to "move away". After 90-120 seconds or rechecking and making a larger and large fuss some one I assume to be the manager asked me what I was missing and "was it a laptop in a black case". Item rescued and I was relieved - until I thought about this and it seemed more and more of a concern. I am not accusing anyone but it took an amazingly short period of time for it to disappear and a strangely long period of time to be "found". Just be careful and be warned. Otherwise T4 is among the best at JFK but shop eat and before security leave enough time to clear security (40 minute queue) and mind your trays!