I've worked at a few jobs over the years where you are wearing a uniform. All the way from the Boy Scouts, the Army, LE/Security work, and corporate retail. Any time you are wearing a uniform, you no longer are an individual to any random stranger/customer. You are (insert employer's name here) and all of your actions are judged so. If you happen to be working for an employer the public views as successful, and you do something sufficiently stupid, lawsuits against your employer will occur, and you're gonna be looking for a new job with a really poor reference from your most immediate former boss. Good luck. Granted (insert big name here) could care less about what happens to you, they do care about the lawsuit and resulting press.
So they put clauses in contracts and make company policies to prevent things from getting that far. Pretty straight forward.
What I do love, though, is the fact that the Brady Campaign is scratching for any little thing to draw out the stupidity as long as they can. Starbucks has nicely asked, a couple times now, for everybody to just back off. For the most part, aside from buying coffee and a few metaphoric pats on the back, the gunnies have shown a willingness to move on. But the Brady Campaign, like an annoying little purse dog, just doesn't know when to stop, and, at least in my mind, just make themselves look more and more idiotic. Of course I don't like them anyway, so I'm perfectly happy with them expending all sorts of money, time, and energy into pursuing the result they want, and will never get, and dragging their own name through the mud in doing so.
Keep it up guys, I'll even donate a shovel to help you dig faster.