In November, the US Justice Department, the FBI and several international police forces raided the homes of members of DrinkOrDie, a group which stripped software of its copy protections and made it available for downloading from the internet. Software which been treated in this way is often known as warez.
In his plea, Sankus, aged 28, admitted that he had caused between $2.5 million and $5 million in damages by allowing the distribution of illegal software, games and movies on-line.
The operation against the DrinkOrDie group took 15 months and a total of 70 search warrants resulted in arrests in the US, the UK, Australia, Norway, Sweden and Finland.
Last week, another member of the group, Robin Rothberg, 34, of Massachusetts, was sentenced by a Chicago court to 18 months in prison. Eleven other members of the group have already been sentenced.