Absolutely. Random people have found his Yelp, Linkedin, Twitter, and Instagram. He also made the mistake of spelling out his name and detailed contact information on the letter. I know that his threat is stupid at best and harmful to Sauce's business at worst, but clearly he's young and inexperienced. Having hundreds (thousands?) of people discussing, criticizing, and examining your details online is terrible. I'm not too worried about posterity, because he has a very generic name, but it could have been much worse.