find out the combination and don't do anything stupid
If your things are in an order that they were not in before or if the locker is open when you get there.
by using a key?
if you leave something in an open locker you should expect that someone is going to take it. How can you say they stole it when they probably feel they found it. It wasn't like they took it out of your backpack or out of a locked locker.
Yes.
Yes, section 23 of the Postal Services Avt 1998.
The answer to the locker problem is every perfect square is a locker that is open.
You have to hit it in the middle of the top half of the locker sometimes it doesn't work but if this is for a school locker then don't do it. This will just cause it to dent and brake and your teacher or professor or whatever would make you pay for it and it's quite a bit of money!
Walking a mile in someone elses shoes.
No, actually. It's not only illegal, it's also very inconsiderate.
Not legally. This would generally be classified as identity theft.
I want to report immigrants using someone elses documents.
Yes, It is a Federal NO NO to open someone elses mail. and to impersinate someone to a Bank its also Federal NO NO. You just dont do stupid things like that.