On Tech Tent this week, reporter Chris Vallance runs us through the serious allegations about lax security levelled at Twitter by its former employee Peiter "Mudge" Zatko. Dr Jon Roozenbeek, of Cambridge University, explains how educating people about how misinformation works appears to be an effective way of informing their online experience. And the makers of a voice changing technology respond to accusations it is increasing prejudice rather than addressing it.