KUALA LUMPUR, Malaysia — Malaysia flipped the switch Monday. Millions of children under 16 lost the legal right to open or hold social media accounts. The move didn’t arrive without warning. Yet its sudden reality sparked fresh debate over protection versus practicality. The rules hit platforms hard. Any service with eight million or more users here — Facebook, Instagram, TikTok, YouTube among them — must now verify ages and block those too young. Noncompliance carries fines up to 10 million ringgit, or about $2.5 million. Parents face no punishment if kids slip through. Verification draws on government IDs or passports. Existing accounts get six months for checks. Underage users then have one month to download their data before restrictions kick in. The Fortune report captured the rollout details and immediate family reactions. Officials cast the policy as necessary defense. They point to cyberbullying, scams, sexual exploitation and addictive design features that keep kids scrolling.…