Probably a lot worse than the tobacco industry in the long term. With a lot more unknown effects and problems.

Again, the problem is not sharing. The problem is that they knowingly manipulate the sharing. How they do that is their problem.

I have no idea how to go about enforcing this. But it's impossible for me to look at it and say "just let it run it's natural course".

And smokers still knowingly smoke, causing themselves and others harm. Because of this (and also arguably for revenue) the behaviour of the multinational tobacco companies is regulated by the governments in the countries they operate in.

Regarding what should be regulated, I’d say that assisting genocide should be blocked for a start.