Depending on the law in your particular state, it may be illegal to use. In NJ, hollow point ammo is illegal.
Thats a common misconception. It is not ilegal to buy or shoot HP's in NJ. Link to NJSP http://www.state.nj.us/njsp/about/fire_hollow.html
It is ilegal to use a HP for a ilegal purpose. If a BG was to rob a store with HP's in the gun than he would be guilty of an additional charge.