The NSPCC has a dog in the race with this one.
If the UK watchdog, watch dog, (NSPCC) are aware of CSAM and they did not report it, are they not committing a criminal offence in the UK?
I thought that professionals, especially in areas of child protection like the NSPCC, were legally bound to report all instances of CSAM and not blame someone else for not reporting the CSAM that they found.