Online multiplayer game Roblox, which has 90 million users worldwide, is marketed at children - but there are fears it also being used to groom them. One mother explains how this happened to her young son.
“They were talking about rape. They were talking sexual activities that were pornographic,” Sarah - not her real name - says, recalling some of the graphic messages sent to her child.
He had been playing Roblox online - where users build their own games and create characters with coloured blocks.
For Sarah, it initially seemed like an “innocent game”.
She had turned on parental controls, so her son - not yet a teenager - could not send messages.
But, over time, she noticed a change in his behaviour.
He would no longer want to join in with family activities he usually enjoyed.
Concerned, she decided to check the game - and discovered he had been communicating with others on a third-party app.