It's implied he would or did come back many times to harass them, but seeing how it was presented in this chapter, I found it a bit too big that just this much would push them to suicide.
Still, I think it's an important discussion to have, especially in Japan where the online thought police can be awful. As a fan of Terrace House that chapter hit the nail on the head. A contestant on this reality show, Hana Kimura, recently committed suicide, mainly because she was harassed online for an incident that ironically staged by the production to make her look bad.