Ever heard of bolt cutters, diamond saws, ceramic cut off wheels etc?
And so the protestors will magically move away when you cut the cable??
You have to lay your hands on them to move them.
"In both cases demonstrators linked their arms inside metal sleeves and refused to let go until after the liquid spray was applied.
Authorities said they used the pepper spray because they were afraid that cutting the metal cuffs would injure the demonstrators."
Bolt cutters and saws would not have worked in this case.