At least 19 Japanese Web sites were recently hit by DDoS attacks to protest Japan's acquisition of disputed islands in the East China Sea.

"Many of the websites were altered to show messages proclaiming Chinese sovereignty over the Diaoyu islands, a Japanese-administered chain Tokyo calls Senkaku, the National Police Agency (NPA) said in a statement," The Globe and Mail reports.

"Chinese hacktivist group Honker Union is being blamed for the attacks, as around 4,000 people reportedly posted messages discussing them on China’s YY Chat," writes The Next Web's Emil Protalinski. "The NPA further confirmed that about 300 Japanese organisations, including the Internal Affairs and Communications Ministry and Tohoku University Hospital, were listed as potential hacking targets on the organization’s message board. "

"The cyberattacks made it impossible or difficult for 11 of the 19 websites to be browsed. ... The cyberattacks tampered with the other eight websites, including those of the Supreme Court and the Tokyo Institute of Technology, leading them to display pictures of the Chinese national flag," Kyodo News reports "The Tokyo Institute of Technology said the website of its Center for the Study of World Civilization came under attack, causing personal data of 1,068 participants in the center's events to be leaked. The data included their names and telephone numbers."