When an author has their books on Amazon and other such sites receive multiple low score reviews in response to something retarded that they have said, even if whatever they were talking about may have had nothing to do with the books. Usually, people who bookstorm haven't actually read the books themselves, leaving reviews such as "Well, if this author feels qualified to talk about things they know nothing about, then I do too."
Dr. Carole Lieberman said that video games cause rape. In response, she got bookstormed on Amazon by gamers.