Video game giants can be slapped with near-$50 million fines if they fail a directive to prevent the grooming and radicalisation of children.Roblox, Fortnite, Minecraft and Steam have received a notice from Australia's eSafety Commissioner requiring them to explain how they are identifying, preventing and responding to serious online harms.Concerns have been raised about platforms being used as a point of first contact by sexual predators to groom children, or by extremists to spread violent propaganda and radicalise them.The "global precedent" has been praised by Australian Catholic University professor Niusha Shafiabady as the latest step in safeguarding children."In the scale that a game like Roblox has, controlling everything is impossible .. but any ways to mitigate these risks that exist is better than nothing," she told the Australian Associated Press on Wednesday.Roblox and Fortnite are among the most popular games for younger children, but both have been embroiled in various controversies.Neo-Nazi, anti-Semitic and violent content has been found on Fortnite, including a map based on a concentration camp where 100,000 people were killed during World War II.Terrorist attacks and mass shootings have reportedly been recreated on Roblox.In a statement to SBS News, Roblox said it welcomes engagement with eSafety on the topic."Roblox has policies that strictly prohibit content or behaviour that incites, condones, supports, glorifies, or promotes any terrorist or extremist organisation or individual, which we work tirelessly to enforce," a spokesperson said