I used to dread the idea of being filmed like a 'spy in the cab' but my views are changing. I worked in a 'secure environment' High Security prison for a while and was surprised that there was no CCTV in the classes; and things did happen. I have seen how 'dashcams' can do so much to assist stupidity and unfairness when incidents happen on the roads. In various teaching scenarios I have been in, if the session had of been recorded would have helped and I think if miscreant students felt they were under scrutiny their behaviour might be much better. Like I say, where I felt it would work against me I was against it, but equally it can assist you on verifying your approach was sensible and reasonable when faced with very bad behaviour, aggression and other incidents. Or would this open the floodgates for SLT's to scrutinise all lessons?