Threatining to give his details was not justifiable and certainly not appropriate. 

Should she be fired for it i dont know. Should she be fired for shaming the company to hundreds of thousands on the internet, yes. 

He wouldn't be afraid of her giving out his business card if he wasn't acting like a total a-hole.

He created his own problem. That's really all there is to this.

"We have his business card you guys want to email him and thank him for holding up the line?"

That doesn't sound insulting to you? The whole time she was speaking to him it was in this sarcastic, condescending tone.

I already checked the topic. she threatened to reveal his personal information.

Again the only real response to him was exactly what she said. "Youre very welcome" is about the only thing you can say to thank you and he escalated it by trying to call her out and saying he doubted it and was never going there again due to a policy she has no control over and a very reasonable on at that. And again, "sorry to hear that we appreciate your business" is the only real thing you can say to that. They are generic response you are told to give to a customer like that.

Check again, the guy said public and the only information she had was a business card (which the purpose of such is to divulge contact info to as many people as possible... hence not personal)

give up. making fun of the custumer as he leaves is anti professional to the extreme. what he did was rude, what she did was worthy of a sue.

the purpose of a business card was already deeply explained to you by another user. and that purpose is certainly not a random person asking strangers if they want your private information so they can harass you through e-mail.

Wrong again. Im the only one explaining the purpose of a business card

lol since when do u need ID to pick up a game.

Here all u need is your name and email or simply your membership card lol.