Nah I disagree for the police. These things can do damage, but they can be very useful for pain compliance.
That bint in the above video is using it ineffectually, but I can tell you right now if she had swung that thing with appropriate force be would have let go of her partner quickly - or weakened him enough so her partner could struggle free.
Further to this, they're very good for leverage. You want someone's arms out so you can cuff them, or make sure they don't possess a weapon when they're on their front - you easily place the baton under the armpit, and leverage it between the ribcage and the arm. Hurts like fuck, and gets the arms out. Ideal.
For example.
Plus, it can be useful as a means to create distance.