Guns dont kill people, people kill people with guns. You can say that if we should ban guns then why not ban knifes or pencils since if those end up in the wrong hands they can be used to hurt somebody. Guns are designed to kill people and only for that while the other things are not designed for that.
Yet for all of these point the gun can end up in the wrong hands, a child can take it and shoot it, a mentally ill person can take this and shoot it and anyone who is angry and thinks shooting is going to help can take that gun and shoot it.
I see that you tried to compare cars and guns but cars are used for driving around and are certainly not designed to kill or injure people. Guns are designed for one thing only and that is killing people or injuring them.''In the two years since the shooting at Sandy Hook Elementary School in Newtown, Connecticut, there have been at least 94 other school, college or university shootings in the United States.'' http://www.telegraph.co.uk/news/
Using the product in a photo shoot is one thing and celebrities are not always fully aware of how the product is made but some celebrities make their own shoes, shirts or makeup line, and often their products are not made fairly, they are made by children,tested on animals or they have unhealthy chemicals in them. The celebrity would not know this if he/she was not involved and responsible for their own product, and it could hurt their reputation.