Hatsune Miku fans everywhere are being rallied to the virtual diva's defence parties unknown have been waging an underhanded campaign against her on YouTube, by filing fraudulent copyright claims against her videos in an effort to get all her songs deleted.
The campaign of mass deletions has been orchestrated against Hatsune Miku and Vocaloid songs hosted on YouTube's various international sites, targeting translated versions. Popular Vocaloid videos which were many years old and had accumulated millions of views have been deleted as a result of the action.
The deletions have been requested by a variety of suspicious parties nobody has ever heard of names featured include "Media Interactive Inc" (who were apparently implicated in the deletion of Lady Gaga's YouTube account) and variations on the name of "Junichi Sasa" (笹純一, 笹金純一, 笹川純一, 笹村純一, etc.).
As the copyright for all original Hatsune Miku songs normally rests with the original creator, not with any company affiliated with Yamaha, Crypton or the record company mafia (except the minority of songs professionally published by these companies themselves), none of these deletions can be considered as anything but fraudulent.
After doinga brief search on google, I found out the name Junichi Sasa is associated with the company Konami Digital Entertainment. I don't know if that exact person is deleting Miku videos, though. A different person could be using this as an alias.