Displacing one web site in Google SERPs (search engine results pages) simply means that another one will takes its place.
Even if Mr Cuban was to influence the top 1000 web sites, they account for such a huge variety of keyphrase sectors that he would only be slicing a miniscule piece of the Internet pie in many, many keyphrase competitions. This type of scheme could have a significant impact in the search engine world but he'd have to stay focused on only one sector at a time.