Heroin is already way past a reputational point of no return, but people are still using it.
I do not disagree. But. Let's see the heavy facebook user at hours 18 and 36 of abstinence, and at week 1 and 2 ... The psychological rewards have physical side effects with physical actions, too.
This is not the same as life threatening DT's, but its also real physical effects.
The key is only a fraction use it. Facebook's intake is way way more than Heroin's.