This happens all the time...No privacy

Not if you're under 18

It's not illegal if it shows up in YOUR mailbox. So if someone's package from somewhere else ends up at your place you can legally open it.

Usually the person it’s addressed to is written on it, so you cant just open someone else’s package.

Some people are too young, and that does not mean their parents are entitled to every facet of their lives. Not giving your child privacy is a form of child abuse which I am completely against.

cuius enim panem manduco, carmina canto