On Friday afternoon, titles of some messages on the bulletin board of the homepage for SBS TV miniseries "Tokyo, Sun Shower" had been changed into "We oppose U.S. beef imports!" and "Lee Myung-bak, step down!" Investigation showed that they had been rewritten. SBS TV discovered the vandalism around 9:30 p.m. and restored the homepage to its former conditions around 10 p.m, but it was unclear how long the messages had been up. SBS said this was not a hacker intrusion, but somebody with manager authority accessing the homepage from outside and changing the message titles.

The homepage of the ruling Grand National Party after suffering an apparent cyber attack

On June 1, the welcome screen of the ruling Grand National Party's website flashed with a picture of a cat and the message "I dislike Myung-bak", posted ostensibly by the GNP Policy Committee. This was clearly a case of hacker intrusion. Two days later, the National Police Agency’s Cyber Terror Response Center arrested a 37-year-old computer programmer identified as Kim and has since been questioning him.

On June 2, the website of the Mobile Police Regiment of the Seoul Metropolitan Police suffered a cyber attack. Its initial screen showed a picture of a polar bear and a phrase "It hurts... if you hit me!" Police presume that attack was the expression of protest against the forceful suppression of recent demonstrations.

The same day, those who logged on to the McDonald's Korea homepage were automatically redirected to a foreign-based adult site. McDonald's said this had “nothing to do with the U.S. beef imports." But many speculate that it was a retaliatory attack as it came at a time when rumors circulated that McDonald's uses American beef cattle older than 30 months, which many believe carries a risk of mad cow disease.

A capture of the website of McDonald’s Korea

The website of the Korea Press Arbitration Commission was hacked on May 27 and remained closed for more than a week. The commission said there was a cyber attack from China that had nothing to do with MBC TV's 'PD Diary' program -- the show widely credited with galvanizing public sentiment against U.S. beef. The attack took place on the day MBC was supposed to air a correction by the Ministry for Food, Agriculture, Forestry and Fisheries about MBC's report on mad cow disease in accordance with the commission's decision.

A computer security expert said the cyber attacks “are primary-level 'script kiddings.' They are so easy that even high school students can download hacking tools and attempt such attacks."

An official with the Cyber Terror Response Center said interfering with websites is a criminal act subject to a prison term of up to five years. “Many hackers are committing this kind of crime without any sense of guilt,” he added.

Whenever cyber attacks are launched on major portal sites, the victims have attracted public attention and become popular search words.

(englishnews@chosun.com )