“DDoS for hire services such as these pose a significant national threat,” U.S. Attorney Bryan Schroder said in a statement. “Coordinated investigations and prosecutions such as these demonstrate the importance of cross-District collaboration and coordination with public sector partners.”

The FBI had assistance from the U.K.’s National Crime Agency and the Dutch national police, and the Justice Department named several companies, including Cloudflare, Flashpoint, and Google, for providing authorities with additional assistance.

Some of the sites named in the indictments reported attacks exceeding 40 gigabits per second, large enough to knock some websites offline for a period of time.

Specifically in the complaint, the Justice Department accused Downthem had more than 2,000 customer subscriptions, and had been used to carry out over 200,000 attacks.

When reached, the FBI did not comment beyond the Justice Department’s statement.