it is just like today - i may have a knife and you have a gun, only those robotic "knife" and the "gun" will be "smart", more powerful than a knife and probably than a gun, at least the robot would shoot much better than an average person, and come with subscription fee.

Also, while people in many places can't get a license to carry various weapons, a large cash flush corporation can push through the regulations Uber-style and get the regulations to allow their robots to carry and use those weapons.