Kinda off the topic...but be glad this didn't happen to you!
I grew up out in the country,...well around my JR year of HS some dicks kept smashing our mailbox...thought they were cool the 1st couple times. Then I took a new mailbox, packed that bitch full of concreate, left enough room for the mail...and put it up. About a week later there was a dent in the mailbox, the concreate was cracked a bit...and there was glass everywhere. They evidentally took a swing, had it bounce back & break their window. Serves the fuckers right!
SOunds like you lucked out.