Is this illegal?

Have police heard it all? A man who was accused of smashing mailboxes states that he didn’t know it was illegal. While police were taking statements, other neighbors came out complaining of the damage to their mailboxes as well. He is accused of smashing multiple mailboxes including his own neighbor’s twice.

http://www.nola.com/crime/index.ssf/2012/04/accused_serial_mailbox_basher.html