Create a system [ call it "BigBrotherBook" ], that:
- Allows everyone to upload photos of themselves eating.
- Has software agents analyze the uploaded data on a continual basis to see what people are doing
So the final element is to have that system create reports on the eating habits of everyone. It can even automatically post such reports directly to public notice boards, the police or most effectively to the people concerned. Each persons "wall" or some such could contain a "likes meat" icon indicating their meat eating status.
Having implemented such a system, a government can then not just pass appropriate legislation, but have some chance of enforcing it.
Obviously such as system is readily modified to enforce compliance to any other arbitrary behavior by a totalitarian state.
Equally obviously, no freedom desiring society would allow "BigBrotherBook" to be created ...