Here is where black / white thinking comes into play.
A person who has a boundary draws a metaphorical line in the sand. They may verbally express that boundary. And then, if someone crosses that boundary who was told about it, they person who created the boundary punches the perp in the head.
The legal version of that is called a tort.
Either way, it's like you rolling through a stop sign. You may have got a fine for doing so, but that may not prevent you from doing it again.
Having a boundary is like drawing a line in the sand and expecting someone who is blind to see the line and not cross it...
It is OUR boundary, not anyone else's.
If someone is going to cross OUR boundary... rather than punching them in a head... it is up to US to be creative on how to live our boundary.
