Is the danger of something determined by the effect it has on a human being who gives it up? What addiction is harder to kick...smoking or texting/tweeting?

It is facing the consequences and having the will power to stop period.

I think the danger of a thing is determined by how likely said thing is to lead to direct harm.

Texting isn't something one typically associates with addiction, it can be easily rationalized as a need, yet it leads to so many deaths. People tend to underestimate the danger present in something so seemingly benign, whereas they know smoking will inevitably harm them.

I suspect it would be harder to stop texting, for someone truly addicted, and for the reason I just noted... As behaviors go, it can easily be rationalized as a necessary act that doesn't always lead to direct harm and thus is acceptable when used responsibly. Problem is, true addicts are incapable of using their addictive's responsibly.