Don't hit people. (Im too old to hit very hard and too scared to get hit by hangry young homeless people, so I try and talk with them rather than hate on them. My verbal skills are a two edged sword. I save my ranting for online. I NEVER rant in public!
For adults the message isn't about physicality. He explains very clearly on page 5 that "Don't hit people" is the version of the message a six-year old understands, but then he goes on use the adult example of "environmental pollution and destruction" and how it hurts people.
If you're purposefully pushing people's buttons, especially just because you're bored, not provoked, then you're hurting people for no reason. Fulghum said, "Play fair," "Don't hit people," and "Say you're sorry when you hurt somebody." Good rules to go by.
He also said, "Clean up your own mess." Better get started.