This isn't "screening". You give the airline your bag and in return they give you a sticker that entitles you to reclaim it. Moreover, if your bag does not turn up the airline is liable to compensate you (up to certain limits). Perhaps, if we were willing to waive any claim to compensation against the airline (which is FT blasphemy!) then we could expect the airline to give up its right to demand the claim check. As long as the airline is contractually obligated to deliver the bag to the right person, I don't see how else this could be accomplished.