Using a "device" to help you gamble at a casino is usually illegal, yes. From the Wired article: the operatives use their phones to record about two dozen spin

Using a "device" to help you gamble at a casino is usually illegal, yes. From the Wired article: the operatives use their phones to record about two dozen spins on a game they aim to cheat. They upload that footage to a technical staff in St. Petersburg, who analyze the video and calculate the machine’s pattern based on what they know about the model’s pseudorandom number generator. Finally, the St. Petersburg team transmits a list of timing markers to a custom app on the operative’s phone; those markers cause the handset to vibrate roughly 0.25 seconds before the operative should press the spin button. Wired says they were arrested under a federal fraud charge. I don't know how that part works, but it's definitely illegal under state laws, e.g. Nevada:   It is unlawful for any person to use, possess with the intent to use or assist another person in using or possessing with the intent to use any computerized, electronic, electrical or mechanical device, or any software or hardware, or any combination thereof, which is designed, constructed, altered or programmed to obtain an advantage at playing any game in a licensed gaming establishment... [1] Applies to anything at the casino -- it's not illegal to count cards at blackjack in your head, but you can't use your phone to do it. [1] https://www.leg.state.nv.us/NRS/NRS-465.html#NRS465Sec075 https://www.leg.state.nv.us/NRS/NRS-465.html#NRS465Sec075