Engadget
Is It Safe To Leave Your Phone's Bluetooth Running All The Time?

Bluetooth flaws in Fitbits, Airoha-based hardware, and similar devices allow nearby attackers to decode location, intercept calls, and steal contacts, phone numbers, and call history. Mitigation includes disabling Bluetooth when idle, setting it to hidden, unpairing from vehicles, and turning off Android Auto auto-start and iPhone Live Listen. Following these steps markedly reduces bluebugging and bluesnarfing risk.