It's a way of fucking with neo-nazis in turn. The three parentheses were originally meant as a sort of euphemism or code: rather than be publicly anti-semitic,

It's a way of fucking with neo-nazis in turn. The three parentheses were originally meant as a sort of euphemism or code: rather than be publicly anti-semitic, people would put the parentheses to highlight how often Jews were being heard from, the idea being that once you notice the amount of Jewish voices around, you'll think this can't just be a coincidence (hence the name "Coincidence Detector.") It wasn't meant to be something those not in the know would get. Jews putting three parentheses around their own names is a way of saying "I see what you're doing. I'm onto you." And non-Jews doing it is just to mess with them.