/b/ board of 4chan) during Project Chanology to attack websites from the Church of Scientology, once more to (successfully) attack the Recording Industry Association of America's website in October 2010, and it was again used by Anonymous during their Operation Payback in December 2010 to attack the websites of companies and organizations that opposed WikiLeaks.
In retaliation for the shutdown of the file sharing service Megaupload and the arrest of four workers, members of Anonymous launched a DDoS attack upon the websites of Universal Music Group (the company responsible for the lawsuit against Megaupload), the United States Department of Justice, the United States Copyright Office, the Federal Bureau of Investigation, the MPAA, Warner Music Group and the RIAA, as well as the HADOPI, all on the afternoon of January 19, 2012, through LOIC. In general, the attack hoped to retaliate against those who Anonymous members believed harmed their digital freedoms.
The LOIC application is named after the ion cannon, a fictional weapon from many sci-fi works, video games, and in particular after its namesake from the Command & Conquer series. The artwork used in the application was a concept art for Command & Conquer 3: Tiberium Wars.
The song "Low Orbit Ion Cannon" on Emperor X's 2017 album Oversleepers International directly references the software.