This kind of lawsuit is not justifiable, at least not in this form. A collective lawsuit, and one that is not a barefaced amoral campaign to cash in on the tragedy could be of some value.
By the way, someone should design an aesthetically pleasing, discretely inconspicuous and Family Sized (based on US families) metal detector-gate that public businesses can install at the entrance without making you feel watched. That someone might make a killing.