You can hear one of the bereaved parents here about 15 mins in:
https://www.bbc.co.uk/programmes/m001yxfn
They are calling for a system where certain words that are used are flagged up. It should be technically doable as forums are able to identify bad language.
Some words eg sex are appropriate for adults in private messages, but not for children, so maybe they could cross reference with a person's age so that the system can decide whether to flag it up for attention or not.