"Now that he's no longer here to fight for himself, to talk for himself, that's what we're here for," said Jackson fan Samantha De Gosson.
Fans and the Jackson family also say the songs are sung by an impersonator, and that Sony released music against Michael's wishes.
"It's just an insult to Michael Jackson. He was a perfectionist, you know, he would never release any of this," said one Jackson fan.
The special administrators of Michael Jackson's estate reached a deal with Sony in March. It allows Sony to create new projects featuring Jackson's unreleased music.
Producer Eddie Cascio says Michael recorded some of the songs on the new album in Cascio's home studio. He told Oprah Winfrey the vocals on it are Michael's voice. But diehard fans aren't buying what Cascio has to say.
"This album is not Michael Jackson's album, and fans should not buy the album. They should totally boycott Sony like Michael asked us to do in 2002," said De Gosson.
Sony says "Michael" is the first release of Michael Jackson material in nine years, an album these fans hope doesn't become a big money-maker.
Calls to Sony headquarters in New York City seeking comment on the protest were not returned.