More than 50 people protested Saturday outside Cincinnati's Scientology location on West Fourth Street, holding signs that urged passersby to honk in support.
The group, calling itself Anonymous, wants Scientology's tax-exempt status with the Internal Revenue Service revoked.
Most of the protesters had their faces covered, either with makeup, hospital masks or Halloween masks, and some wore badges with nicknames.
A Cincinnati police officer stood outside the Scientology door watching protesters across the street.
The protest coincided with others across the country, scheduled two days after the birthday of Scientology's deceased founder, L. Ron Hubbard.