Try to understand why social networks are important for your son, for your daughter.
The others grant him a good image, they congratulate her. Your teenager gets a lot of likes. And you, parents, do you congratulate them?
Ask your teenager: Would you like a life like the ones you see in social networks? What do you say about yourself? Real things or not quite? Or things you would like to be real? Is your daughter happy with her life? Does your son wish he had another life? Is he jealous of others?
Social networks help your teenager forget about problems. How is your child doing, generally speaking? Is he well integrated? Does she have friends in real life? And at school, how are things going? How are things at home? How does he handle fights within the family?
Support your teenager, help him or her to find resources to overcome difficulties. If difficulties remain, find support from specialized professionals, for your teenager and for yourself.