How do I prevent my young son from talking to girls online?

A mother can prevent her son from speaking with women online through several means: supplicating for him that Allah purifies his heart and protects his chastity, offering advice and reminding him of Allah and His punishment, seeking assistance from relatives who have influence over him, and giving him materials that address the issue. He should be kept away from bad company and encouraged to associate with the righteous. If these means are not effective, then the internet should be cut off from him at home. Finally, initiating his marriage if possible; otherwise, advising him to fast.