News of GrayKey, an iPhone unlocking device, has highlighted the importance of mobile security. With GrayKey, a user can connect a cable to an iPhone and unlock it, bypassing or brute forcing the user’s passcode.

While the makers of GrayKey only sell the device to law enforcement, there’s no such thing as an exploit that only works for the good guys. You should assume that bad actors also know about whatever security flaw GrayKey exploits.