With the intent of siccing a mob of people on someone to harass them online? No, never. In the article, the problem is not that the women discussed the fact that they had received harassing emails, but that they attributed those emails to a particular person without any proof that that is true.

"I received an anonymous harassing email" - true statement, not libel

"I received an anonymous harassing email and it was definitely from this guy" - if you can't prove it, could be libel.

See the difference?