Called Operation Web Snare, the investigation ran from June 1 to Thursday, and targeted a range of cybercrimes, including identity theft, fraud, counterfeit software, and computer intrusions.
Investigators said they identified more than 150,000 victims with losses totaling more than $215 million.
Among the charges, six men were arrested in California in connection with what officials described as the largest and first-ever case involving sophisticated denial-of-service attacks for commercial advantage.
Jay Echouafni, CEO of Orbit Communications Corp., in Massachusetts was indicted on charges of conspiracy and causing damage to protected computers. According to officials, Echouafni and a business partner hired hackers to launch DoS attacks against Orbit Communication's competitors, causing losses of more than $2 million.
Also in California, a federal grand jury indicted a Romanian man and five U.S. residents on charges that they conspired to steal more than $10 million in computer equipment from Ingram Micro.
Operation Web Snare was a cooperative effort between U.S. Attorney's offices, the FBI, the DOJ, and a variety of other federal, state and local law enforcement agencies.