I am shocked that this is even a question. PARENTS should have a lock on the door. CHILDREN should NOT have a lock on their bedroom doors.
We have witnessed a large contingent of the “yeshivish/chassidish” world organize pointless asifa after pointless asifa when all along sane and normal parents everywhere know that the only thing that has a chance of stopping your kids from doing anything horrible is open, honest communication and a watchful and caring eye. Just exhibiting your child you are there for them.
And there are those of us who actually believe that with all our children have access today that we should actually hand them the gun and allow them to lock themselves in a room to do as they please?
What WORLD are you people living in????????