Levy has argued scores of cases in United States Courts of Appeal, and in the
United States Supreme Court, as well as writing briefs for parties in seven other cases. In arguing against the issuance of
prior restraint in
Bank Julius Baer v. Wikileaks, he had the insight that the case had been filed without
subject-matter jurisdiction. His work in such cases as
Lee v. Makhnevich and
Prestigious Pets v. Duchouquette, opposing the enforcement of
non-disparagement clauses in consumer contracts, presaged the adoption of the federal
Consumer Review Fairness Act that made such clauses illegal. In
Dimondstein v. Postal Workers, he established that the right of intra-union candidates to have campaign literature distributed to union’s list of membership addresses included the right to send literature by email. In
Smith v. Garcia, he established the right of Internet speakers to oppose orders compelling the "delisting" of their blogs from search engines. He has litigated cases under anti-
SLAPP laws in several different states and advocated the adoption of new laws of this type as well as toughening existing ones. Courts adopting Levy's test in
Dendrite include the
Maryland Court of Appeals, the
US District Court for the Western District of Washington, the
New York Supreme Court, Appellate Division, the
Arizona Court of Appeals in
Mobilisa, Inc. v. Doe, the
California Court of Appeal for the Sixth Circuit, and many others. In
Doe v. Cahill, the Supreme Court of Delaware adopted two of Dendrite's four prongs. Levy's work on cases involving anonymity is discussed in
Jeff Kosseff's 2022 book
The United States of Anonymous. ==References==