Operation Buccaneer
The US Customs Service's coordinated strike against the top tier of the warez scene in December 2001.
On 11 December 2001 US Customs, working with police in the UK, Finland, Norway, Sweden and Australia among others, carried out some seventy searches on a single day. The target wasn't downloaders but the source: the groups that cracked and released software and the topsites where releases first landed. DrinkOrDie was the main target, but Razor 1911 and several other groups were hit as well.
The investigation had run for over a year with undercover agents inside the groups, and produced convictions in several countries. It changed how the scene behaved: more encryption, fewer members, tighter circles. That releases kept coming regardless showed that warez was a structure rather than an organisation, and you can't arrest a structure.