Nearly two out of 10 primary and secondary school students were either perpetrators or victims of cyber bullying, carried out often by acquaintances while victims react with passivity, a report showed Tuesday.

Compiled jointly by the Korea Communications Commission and the Korea Internet & Security Agency, the report was written based on responses from 3,000 students from elementary school fourth graders to high school seniors on a survey from Oct. 22-Nov. 13 last year.

The report said 17.2 percent were victims of cyber bullying in the past year while 17.5 percent said they were online attackers.

Compared to 2014, the number of victims fell 1.8 percentage points, but the number of perpetrators increased 3.5 percentage points.

Many of the attacks were verbal (15.8 percent), and the target of the attacks were almost evenly divided between acquaintances (47.1 percent) and strangers (48.9 percent).

The older the perpetrators, the weaker the sense of guilt, the report showed. When asked if they thought their behavior was justified, 22.8 percent of elementary school students said so, compared to 43.6 percent of high school students.

On reasons for cyber bullying, 43.9 percent said they were taking revenge for something that was done to them, while 34.8 percent said that they disliked the victims or were angry. Another 2.8 percent said they did it for fun or out of stress.

Victims said they wanted to retaliate against the attacker (31.7 percent) or became depressed (18.4 percent). The report said 5.8 percent of them thought of suicide.

Despite such responses, 39.1 percent of the victims said they stopped at changing their online IDs or deleting e-mails, while 27.5 percent said they did nothing. The number of those who actively reported cyber bullying to authorities was just over 20 percent. (Yonhap)