It's absurd. Instead of a single large soda, people will just buy multiple small sodas for a net gain in sugar intake and an increased cost. People shouldn't be drinking that stuff, but the government shouldn't mandate diet.
Yes, because it worked so well for prohibition. Who wants to make bank and join my soda-smuggling gang?
As a New Yorker and a liberal, who hates soda, let me see. 1) yes, the libertarians have a point here. People should be free to poison themselves. Banning a "size" of something is stupid. It's like banning packs of 40 cigarettes but not packs of 20.
2) as part of the city's anti-sugar education campaign, I think it's awesome. There used to be these totally nasty anti-sugar ads with gobs of human fat exploding out of soft drinks. So it's good to see them trying to promote public health in this way, same thing as cigarette ads / taxes / warning labels etc. Over decades, it saves thousands of lives. People are mostly sheep, face it, get real. Just because you don't think you are, doesn't change the basic facts. Most people get their nutrition advice from a billboard.
If you are new to the PB - please ignore ALL of this stuff, until you've read the book, or at least http://www.marksdailyapple.com/primal-blueprint-101/ and this (personal fave): http://www.archevore.com/get-started/