Broader groupings of Big Tech may also include Twitter and Netflix. Occasionally, despite being an automaker, Tesla has also been referred to as a Big Tech company, an opinion subject to wide debate.[20][21][22] The concept of Big Tech is analogous to the consolidation of market dominance by a few companies in other market sectors such as Big Oil.[23] "Big Tech" may also refer to historical versions of this concept, with the likes of Microsoft, IBM and AT&T considered to be dominant companies in this industry in the mid to late 20th century.[24]