Earlier in July, Google filed a court document with objections to the 68 adtech witnesses called by the Department of Justice for its upcoming adtech antitrust trial, challenging a list that reads as “who’s who of adtech.” The witness list represents a cross-section of the industry with execs from adtech companies, publishers, and ad agencies. Some of the witnesses are testifying live and others are submitting testimonies via deposition.

Among the objections, Google argues that Brian O’Kelley, adtech veteran and former CEO and co-founder of AppNexus, has a “lack of personal knowledge,” according to the document.