First, it's not clear what exactly you'd sue anyone for--that is, even when an action is improper, you generally need some injury or economic damage to sue, since the law only provides compensation for injuries or economic losses. No injuries or losses, nothing to sue for.Second, businesses are typically only liable for the actions of their employees--1) When those actions are taken in the line of business/as part of their job; or2) When there was knowledge of employee wrongdoing, but the employer allowed it to continue.Since it is highly unlikely that what this employee did was part of his/her job or employment, unless you can show that the store knew about what (s)he was doing and allowed it to continue, you would not be able to sue the store even if you could show some damage justifying compensation. (You could still sue the employee.)