Nomadic empire
The Xiongnu were a confederation of nomadic tribes from Central Asia with a ruling class of unknown origin and other subjugated tribes. They lived on the Mongolian Plateau between the 3rd century BC and the 460s AD, their territories including modern day Mongolia, southern Siberia, western Manchuria, and the modern Chinese provinces of Inner Mongolia, Gansu, and Xinjiang. The Xiongnu was the first unified empire of nomadic peoples. Relations between early Chinese dynasties and the Xiongnu were complicated and included military conflict, exchanges of tribute and trade, and marriage treaties. When Emperor Qin Shihuang drove them away from the south of the Yellow River, he built the famous Great Wall to prevent the Xiongnu from coming back.
Xenu
On December 24, 1994, the Xenu story was published on the Internet for the first time in a posting to the Usenet newsgroup alt.religion.scientology, through an anonymous remailer. This led to an online battle between Church of Scientology lawyers and detractors. Older versions of OT levels I to VII were brought as exhibits attached to a declaration by Steven Fishman on April 9, 1993, as part of "Church of Scientology International v. Fishman and Geertz". The text of this declaration and its exhibits, collectively known as the Fishman Affidavit, were posted to the Internet newsgroup alt.religion.scientology in August 1995 by Arnie Lerma and on the World Wide Web by David S. Touretzky. This was a subject of great controversy and legal battles for several years. There was a copyright raid on Lerma's house (leading to massive mirroring of the documents) and a suit against Dutch writer Karin Spaink—the Church bringing suit on copyright violation grounds for reproducing the source material, and also claiming rewordings would reveal a trade secret.