Last Summer I was at a Mc-something in Winchester, VA with my wife. Behind us was a mother with a 9 YO kid. Across the way were 3 teens that were effing everything under the sun, including calling another in his party some pretty vulgar stuff for taking some fries. After about the 5th f-word, I approached the table and asked them to watch their language because there were children around. While the teen tried to argue with me about the value of his "stolen" fries, I told him, "I don't care. Watch your language around kids. This needs to stop now."
While I was having that "conversation", the mother mouthed the words to my wife, "Thank you."
A few minutes later, the same teens uttered something about "s*it", and then quickly apologized for their vulgarity. They left shortly after.
It's pretty sorry that no one else sensed the need to say something, particularly the management of the establishment. Their fries lack enough quality control, so why would I think that they would care enough to protect the interests of their patrons?
Yes, I was carrying (as always), but that's irrelevant since I didn't perceive a life-threatening situation. Nearly 50% of people here carry, so that's no big deal. What's wrong is that no one had the courage to stand up and confront 3 mouthy teenagers who are contributing to the "adult education" of a kid.
To the OP and to @cmhbob's point, isn't it sad that it took a 50 YO grandmother to say something? Where were the real men who should have said something in her place? You don't need a gun to be a man and stand up for what is right.