"We had already submitted a contract with the organization that provides this billboard and I guess the workers were ordered to take it down this morning," said Henry Huerta from the C.L.E.A.N Car Wash Campaign
Union leaders and their supporters gathered at the corner of Vermont and Hollywood anyway as part of a campaign to help car wash workers who want to form a union.
"All workers no matter what their race, their gender, their national origin or their legal status have the right to form a union," said Connie Leyva from the California Labor Federation.
Wednesday's rally included members of congress along with AFL-CIO president John Sweeny.
"The reason we are here is to let people know that there is a cause and that we need to raise our voices," said Pedro Guzman, a car wash worker who told Eyewitness News he had fell victim to intimidation.
Organizers of the news conference held the event at the Vermont Car Wash in Los Feliz because workers here have long complained of unfair labor practices and retaliation.
Organizers of Wednesday's rally say the billboard was removed because the owners of the Vermont Car Wash complained.
Earlier this year, the Los Angeles city attorney filed criminal charges against the owners and a manager, alleging 220 counts of criminal misconduct.