you have to show this 'future-illegal' action is harmful first by demonstrating harm.

That's why i used the sugar example - it's starting to be demonstrably harmful in large quantities that are being used.

I am against preventative "harmful" laws, when harm hasn't been demonstrated, as it restricts freedom, adds red tape to innovation, and stifles startups from exploring the space of possibilities.

I can understand that stance. The trouble is, with more power and more technology, more harm can be done, much quicker. This will become a freedom vs. survival issue, and by definition, freedom is not going to survive that.

> starting to be demonstrably harmful

Starting?