You could be sued for negligence.  Negligence is the failure to exercise due care (that degree of care that a reasonable stun gun owner would have exercised under the same or similar circumstances to prevent foreseeable harm). Your liability would include the injured person's medical bills, pain and suffering (an amount in addition to the medical bills) and wage loss.If you are sued for negligence, you can assert the defense of assumption of the risk.  Assumption of the risk means that the party suing you, recognized and understood the danger of the stun gun and voluntarily chose to encounter it by turning it on, taking off the cover, and pushing the button while in contact with his/her skin.Another defense you can assert is contributory negligence which means the person suing you contributed to his/her own injury.DON'T WORRY ABOUT IT.