[being followed and stared at in public]
Thread: Should I have said something?
Retrieved: 07/26/2014

Asking if he worked there probably wouldn't hurt anything... unless he was one of the mall ninja security types, or a wannabee security type, or a simple nutjob like the one who made the news a couple of weeks ago, who jacked up a carrier and demanded to see his "papers." At gunpoint.

Facing an irritating jerk down is fun, but usually the best thing is not to engage them at all. In full Monday Morning Quarterback mode, my opinion is that you should have just ignored him and continued about your lawful affairs.