Not every, but those that are not usual, that have some strange weight/properties for their kind. Or you'll some day let in a trojan horse... I bet every perso

Not every, but those that are not usual, that have some strange weight/properties for their kind. Or you'll some day let in a trojan horse... I bet every person entering the building is security checked, you don't want anyone unexpected or with some paint or knife near 1 million $ stuff. Plus bag checks at least in places open to public have become usual today.