I don't agree with this. Addictive, unless we're talking about a chemical substance or something like that, is a subjective thing. At some point, books, movies, comics, etc, etc might have been considered addictive. Social networks in general should be banned for underage people, that's the thing. And the social network itself should be liable for verifying the age its users, like a nightclub is liable for people who…
The difference compared to a book is that a book is not personalized for each individual reader, so the example is not a good one IMHO.