Are couriers above the law?

It is against the law for someone to simply walk into someone’s unlocked home, or enter their unlocked car for whatever the reason without having permission (invite) from the owner of the dwelling or owner of the vehicle. 12-05-2014: USPS entered my home. He didn't ring the doorbell, wait four seconds and he entered the front door. He had no reason to believe anyone was home at the time - but that is besides the fact. Luckily my unfriendly (to trespassers), my German shepherd was not in the room at the time, and I was able to identify him as a USPS employee before accidentally identifying him as a home invader. I reported this three times to USPS - it took two weeks for them to get back to me (each time I had to tell the story again and again). I was told this is a complete violation of what they are trained to do and the person will be dealt with. 4/16/2015 (today): Same USPS employee. It was 72 degrees out, not a cloud in the sky - so he decided to enter our parked car and leave the package there instead of the front porch like a normal delivery person would have done. I know he did it being as he wrote a note he did it (I saved the note). I understand that he may have no criminal intent by doing these things, but I don't know him. I don't know his past, or what he is thinking. I certainly do not trust people. Because outside of ignoring my complaints entirely, they haven't done anything to fix the issue. When he entered my home, he could have knocked. My 1 year old daughter over (she is often near the door) and injured her (he opened the door very quickly and stepped in). If anything is missing in my car, guess who the number 1 suspect will be? The guy that left the note saying he was just in the car. I can't for the life of me figure out why this would be acceptable behavior in this state.