Seat belt laws came much later than cars. It used to be a personal decision to wear one or not. Same goes with drunk driving. Gambling is tightly regulated and

Seat belt laws came much later than cars. It used to be a personal decision to wear one or not. Same goes with drunk driving. Gambling is tightly regulated and controlled, although it used to not be. Strong and highly addictive drugs were sold in corner stores. All of these conditions had a negative effect on society, but individually could be considered one's personal responsibility. The negative effect in aggregate was considered strong enough to have to regulate. People are social, and network effects of social media effects are strong. Seems like it fits a similar enough niche to warrant regulation.