Embracing this attitude, various books have been published espousing such an ethos, established New Age centres have held spiritual retreats and classes aimed specifically at business people, and New Age groups have developed specialised training for businesses. During the 1980s, many prominent U.S. corporations—among them IBM, AT&T, and General Motors—embraced New Age seminars, hoping that they could increase productivity and efficiency among their workforce, although in several cases this resulted in employees bringing legal action against their employers, claiming that such seminars had infringed on their religious beliefs or damaged their psychological health. However, the use of spiritual techniques as a method for attaining profit has been an issue of major dispute within the wider New Age movement, with prominent New Agers such as Spangler and Matthew Fox criticising what they see as trends within the community that are narcissistic and lack a social conscience. In particular, the movement's commercial elements have caused problems given that they often conflict with its general economically-egalitarian ethos; as York highlighted, "a tension exists in New Age between socialistic egalitarianism and capitalistic private enterprise".