Olivier is a Professor of Law at Fordham University and a Senior Policy Research Fellow at Columbia University's Knight First Amendment Institute. His research is in information and communications law and policy. His most recent writing, scholarship, and public speaking engagements are on online intermediary liability, commercial surveillance, artificial intelligence, "network equality," and "broadband localism".

The National Science Foundation and the John S. and James L. Knight Foundation have awarded him grants to support this work. He was a Senior Advisor to the Chair of the Federal Trade Commission from 2021 to 2023. Olivier teaches Legislation and Regulation, Administrative Law, Information Law, U.S. Data Protection Law and Privacy, and information law related courses. At Fordham, he has been the Director of the McGannon Center for Communications Research, the Academic Director of the Center for Law and Information Policy, and a research affiliate at the Center on Race, Law, and Justice.

Before entering academia, Olivier was a Karpatkin Fellow in the National Legal Office of the American Civil Liberties Union in New York City and a litigation associate at Jenner & Block, LLC, in Washington, D.C. He serves on the boards of the Open Markets Institute and the Future of Privacy Forum. He has been the board president of the ACLU's New York affiliate and has served on the Advisory Committee for the Cyber Civil Rights Initiative.