Online multiplayer game Roblox is marketed at children - but there are fears it also being used for grooming.

A California man has been arrested for abducting a 10-year-old child he reportedly met on social media apps Roblox and Discord, authorities said Wednesday.

Roblox is a huge sprawling world of games which is sometimes described as a kind of primitive metaverse. It's one of the most popular children's games in the world.