Korea has something equivalent to the social security number called "Ju Min Deung Rok Jung Bun Ho", which literally means resident registered proof number. You need a valid number to register to any site.

Internet has been the medium for the Korean people to quickly organize protests against the government and the place where all rumors regarding celebrities start. The Korean government simple wants to have people reliable for the comments they make on the internet as well as find those people who organize protests. The government or the current president probably wants the latter while using the former as a strong case to do so.

[btw, I don't think Korean people glorify suicides as the Japanese do; I'm a Korean and at least the people around me and I do not think suicide is something to be glorified.]