Taking that further, it could mean the focus is even more intense on those who do go out, and when you go out. I suppose you could try to measure this by finding historical statistics on where people spend their time, inside our homes our outside. After dealing with confounding factors like decreased employment.
[1] http://thedailyjournalist.com/theinvestigative/are-the-inter...
[2] https://www.sciencedaily.com/releases/2010/11/101130111326.h... (although I'm pretty sure this extract misinterpretates some parts!)
I could certainly see how, for example, repeatedly checking your phone could mirror the behavioral aspect of smoking cigarettes. However, losing your phone won't cause withdrawal symptoms like headache, nausea, or fatigue.
Also, I'd agree that social behavior being focused around online interaction could potentially serve as a deterrent (or at least distraction) from drug use / crime. Based on Todd Kendall's paper [Pornography, Rape, and the Internet](http://idei.fr/sites/default/files/medias/doc/conf/sic/paper...), porn has been responsible in some part for the decreasing rate of rape, but not other crimes. I can't find much research on non-rape crime being affected by internet use, but the St. Helena TV study by Tony Charlton did show that aggressiveness in children was reduced by the introduction of TV. Obviously TV is far less interactive than web-browsing, but it's the most similar study I can find. :P
Think about it: Even the worst "physically addictive" substances, let's say heroin, will be completely clear from physically in 7-10 days. Two weeks tops. Anybody can put up with that and, in fact, many addicts do it all the time. If that was the differentiating factor, locking up an addict would work because they would come to their "senses" after no longer physically dependent. Obviously, that's not how it is. Real addiction is something much deeper and cognitively still mysterious. Physical withdrawal (those first two weeks of hell) is called, in the treatment community, the easy part.
I think when most people use the "physical dependence" reference like you did, they are really trying to categorize and emphasize (internally or externally) that among substances and behaviors that are addictive, certain ones more often consume a persons entire being. This process is still a complete mystery and even if people can't or won't accept the amazing power and bizarre scope of cognitive function...it is certainly not 'physical dependence' and I therefore don't think there is any real need to continue with that minor classification.
To be successful, a person has to somehow manage & deal with PAWS, while also facing life, and the deeper causes of their addiction. This is why I am an advocate of recovery that includes bupenorphrine. It allows a person who has the right motivations the space to recover.
It is an unjust tragedy the way this country/world treats people who suffer from addiction.