Anything involving tagging content, or changing the incentives of publishers and posters could be a nice third option. Of course there is no single answer, that would just be turning a false dichotomy into a false trichotomy.
As an analogy, a city might think unhealthy soda is causing problems for its inhabitants. Saying "not our job" would be the status quo. A nanny state would ban sales of soda. Requiring clearly displayed nutrition facts would be one of many "third options" in between these extremes. Other options could involve a new tax, or subsidizing healthier drinks, or asking schools to cover the topic in health classes, or producing a series of public service ads, etc. etc. There's a whole continuum of potential actions.
As an analogy, a city might think unhealthy soda is causing problems for its inhabitants. Saying "not our job" would be the status quo. A nanny state would ban sales of soda. Requiring clearly displayed nutrition facts would be one of many "third options" in between these extremes. Other options could involve a new tax, or subsidizing healthier drinks, or asking schools to cover the topic in health classes, or producing a series of public service ads, etc. etc. There's a whole continuum of potential actions.