RF Safe founder John Coates publishes an open letter urging YouTuber MrBeast (Jimmy Donaldson) to make any potential “Beast Mobile” offering explicitly child-protective and “Li‑Fi compatible,” arguing that phones carried close to the body could scale long-term RF exposure among children. The letter frames current regulatory compliance as insufficient for a youth-focused brand and claims that “non-native EMFs” may disrupt biological timing and redox processes via an “S4–Mito–Spin” framework. The piece is advocacy-oriented and does not present new study data in the provided text.