Don't do this. It's against the unwritten rules of being a fan.
Oh, there are unwritten fan rules, too. Don't do the wave. Don't swear in front of children. Don't cheer for Shane Victorino. But this one's new. Don't assume that everyone is going to root for a team in the exact same way you do, and don't rip a freaking home run ball out of someone's hands if they're unwilling to throw it back. I'll bet Mr. Cool Visor wouldn't have done that to a fella his own size.
Actually, if that ball instantly becomes property of the person who came up with it, I'll bet there are written rules dealing with that sort of thing. Most likely, though, the only punishment the guy will receive is that he'll spend the rest of his days as someone who would wear a visor and rip a baseball out of a woman's hands because it fits with his personal baseball-related dogma.