The authorities can't seize your property. They have to give it back upon your departure, so I would say that guard wanted the Little Battle Flag to play with himself. I mean, what could you do with a hacky-sack. You can't put enough explosive in it to do anything. and Oh!!! you are going to kick it around a little before you plant it????
Most Security Guards are wanna-ba Cops who can't meet the qualifications or mental criteria to be a Cop. Then there are those like me who are tard Cops,,,,LOL