LOIC was utilized by Project Chanology, an offshoot of the Anonymous group, to attack Scientology websites, then by Anonymous itself to successfully attack the Recording Industry Association of America's website in October 2010,, and again during Operation Payback in December 2010 to attack the websites of companies and organizations that opposed WikiLeaks. LOIC was utilized by many attackers, despite the fact that a network firewall could easily filter out network traffic it generates, thus rendering it only partly effective.
More than 30,000 downloads of the tool were reported to have occurred between 8 and 10 December 2010. If an attack is not routed through an anonymization network such as Tor, traceable IP address records can be logged by its recipient. This can be used to identify the individual user conducting DDoS attacks from logs kept by their ISPs. On January 27, 2011, five people were arrested in the UK in connection with the Operation Payback attacks, while in June 2011 a further three LOIC users were arrested in Spain for their involvement in the web attacks. On 14 June 2011, it was reported that Turkish police arrested 32 individuals who allegedly attacked government websites in protest against the introduction of state level web filtering. The individuals are thought to be members of Anonymous that used the LOIC tool in their protest. .