Facial recognition is a great idea in mind. You can open your devices by simply looking at anything! The reality of the matter is that it causes many more problems when brought out to the world. Right now, while using a device with a face camera on it, any computer hacker can stream and record your face with out you even realizing. When saying the word hacker, many just assume its a single person who just snoops around stealing info but that is not always the case. Many hackers are employed by the FBI and CIA and are working for them to steal these peoples info. What for? To protect against potential terrorist attacks.
Originally thought of to stop non-citizens from crossing into America, the FBI had already spent $10.6 million before 9/11. After the attacks millions of more dollars were spent in order to prevent this from ever happening again. What used to take 2 weeks to identify someone now takes less then 3 mins and although it sounds good for law abiding citizens, it is still being used against them to determine if they are criminal or not. Once the FBI or any hacker over seas or not grabs control of your camera, they take your face and can use it for many different purposes. From storing it into data bases to using it to print out fake ID cards, your face is theres now too.
When it comes to finding a solution for the problem at hand, the best idea is to just stick to passwords and finger print. Now although that will most likely not happen considering the millions spent on this project, the next best solution is to cover your cameras with tape. This will prevent hackers from secretly recording you and sharing your personal business.