I doubt that you'd be using foul language in a public place. This idiot (cell phone user) got what he deserved but unfortunately political correctness, which rules our society, will always slam the defender of good while evil goes its own way free and happy.
In most instances, you would be correct. However, if I did choose to, it's my choice. I don't think it's illegal. Even if it is, not this guy's job to enforce it.