The Ninth Circuit has granted a rehearing en banc in Martinez v. ZoomInfo Tech., Inc. concerning the appealability of denial of anti-SLAPP motions under the collateral order doctrine. .
Ninth Circuit has treated California anti-SLAPP statute as substantive law, refrained from applying Erie doctrine to question whether anti-SLAPP motions generally should be precluded in federal courts absent direct conflict. Ninth Circuit recently reaffirmed their position.