The Globe and Mail reports in its Thursday edition that social-media companies collectively made more than $11-billion (U.S.) in U.S. ad revenue from minors last year, according to a study from the Harvard's School of Public Health published Wednesday. An Associated Press dispatch to The Globe says that researchers want government regulation of social media since the companies that stand to make money from children who use their platforms have failed to self-regulate. They say such regulations, as well as greater transparency from tech companies, could help alleviate harms to youth mental health and curtail potentially harmful advertising practices that target children and adolescents. To come up with the revenue figure, the researchers estimated the number of users under 18 on Facebook, Instagram, Snapchat, TikTok, X (formerly Twitter) and YouTube in 2022 based on numerous sources, including data from the U.S. census. Researchers and lawmakers have long focused on the negative effects of social-media platforms, whose algorithms can drive children toward excessive use. Meta Platforms, which owns Instagram and Facebook, is also being sued by dozens of states for allegedly contributing to the mental-health crisis.