the phaser fire alert
Actually, it would be fun if this could be stated to have been a feature back in TOS already. After all, none of TOS actually contradicts this: all the firings of hand phasers aboard the ship at kill setting were by authorized personnel and may have been duly logged in a forensic file rather than routed to the alarm klaxons, while all the criminal use of phasers (such as in "Conscience of the King") would have been at other settings (stun, self-destruct). That the alarm itself never actually went off in TOS need not distract us from following this interpretation.

Timo Saloniemi