Some poorly shot cellphone video caught 'Ri Ri' assaulting a fan at her concert after he or she wouldn't let go of her jacket. 

We can't really tell from the video if who Rihanna hit was the person holding the camera, or if it was someone different. Either way, right place, right time. Now the person who got hit totally should have left their hands off Rihanna, because anyone who's ever been to a concert and sat front row knows security is tight.

In this case, it seems as thought Rihanna took matters into her own hands. We definitely smell a lawsuit.