in proving? Anyway...questions can only be answered once.
No.
Without permission-yes.
Contact your local post office. They may refer you to a postal inspector.
It's actually against the law to open someone else's mail. You can put it back in your mailbox so it can be sent to the right address, or you can get a pen & write 'return to sender' on the envelope.
Of course, you can that is invading your privacy.
Post on their wall, send them an message.
No. Posting a picture of someone without their permission is illegal.
Not unless it is done for commercial purposes.
You can like or love someone if you favor how they act around you, treat you, etc. My personal 'likes' however, are private and so are everyone elses. So don't post questions like this because they are very personal and nosy, even rude!
In England and Wales, it is a criminal offence to interfere with other people's post without legal permission, excuse or authority (for example, a parent to open a baby's birthday card etc.. or post office staff to open a undelivered letter without a return address in order to deliver it back to the sender)
"It's gone AWOL" means that someone or something is missing or absent without explanation. AWOL stands for "absent without leave," typically used in a military context to refer to someone who has left their post without permission.
To mention or tag someone, include the @ in a status or post.