Why did ranchers view barbed wire as a threat?

Barbed wire was a way to stop other ranchers' livestock from getting mixed up with another rancher's livestock. It also was a way to stop squatters from making a homestead on land that wasn't theirs. There were a few free-range cattle drovers back then that didn't own land but grazed their cattle wherever necessary. Barbed wire prevented that as well, and created a kind of necessary ownership of the land.