It is possible that other people's insecurities can actually end up making others feel insecure, vulnerable, exposed, and criticized. You might notice when someone makes a point (I mean a loud, very noticable point) of pointing out something you did wrong.....you kind of wonder how they benefit from being the critic. Maybe, it takes the focus off of them, it even makes them less defensive. Feeling high and mightly, they put others down which enables them to feel worthy at the expense of another. By being over critical of others this feeds their paranoia.
If we ignored this behavior, would the hunger for their security still be satified? Conditioning them to feed their challenge another way by not giving acknowledgement to their demands may persuade them to monitor who they choose to use as a stepping stool.