Earlier quoted context omitted.
My first thought was that GP was saying DefCon attendees would be counting cards, which is an effective and legal way to beat the house[1] (until you're caught and banned from the casino). 1. https://www.freep.com/story/entertainment/nightlife/2016/04/...
'legal' has no meaning here when it's against every single casino policy in the world.
There’s a huge difference between: “if you do X, you will be asked to leave” and “if you do X, the police will arrest you”
Like, when I invite someone over to a dinner party, it is against my policy to insult my dog. If you do that I will kick you out (not actually, he’s a dumb klutz, you can insult him all you want), but that doesn’t make it illegal to insult my dog.