Bit torrent sites are very popular with those who don't wish to pay for copyrighted video, music, and apps, which is why law enforcement officials rightly try to shut them down and put those responsible for running the sites in jail. iTunes purchases associated with a specific Apple ID have just put the alleged owner of KickassTorrents (KAT), Artem Vaulin, under arrest.
At the time of Vaulin's arrest, KickassTorrents was the world's most visited illegal file-sharing website and was responsible for the unlawful distribution of over $1 billion in copyrighted materials. Vaulin is from Ukraine, and was arrested in Poland where he is awaiting extradition to the United States.
The US government made an identification of an iCloud email address that belonged to Vaulin, then sought a court order to compel Apple to provide iTunes purchase records for that address. The iTunes transactions were then tied to specific IP address, which was seen logging into the KAT Facebook account later that day. This happened numerous times. From the government's complaint (via TorrentFreak):
"Records provided by Apple showed that email@example.com conducted an iTunes transaction using IP Address 126.96.36.199 on or about July 31, 2015. The same IP Address was used on the same day to login into the KAT Facebook Account. Then, on or about December 9, 2015, firstname.lastname@example.org used IP Address 188.8.131.52 to conduct another iTunes transaction. The same IP Address was logged as accessing the KAT Facebook Account on or about December 4, 2015."
Apple provided the government with personal details of Vaulin after the IP address cross references with KAT's Facebook account was revealed to the company. A federal court in Chicago has now ordered the seizure of several KAT domain names, essentially shutting the sites down.