Is it ok to beat the crap out of someone if you catch them stealing from your mailbox? Seriously, if anyone ever sees anyone taking or adding anything to multiple mailboxes, call 9-11 and write down the license number. One of the tricks these folks use is to go from mailbox to mailbox opening it up and putting their landscaping card or maid service cards in. They harvest anything that looks interesting at the same time. It is illegal to place anything in a mailbox unless it has a stamp on it.