A San Francisco activist, a local attorney, and the American Civil Liberties Union (ACLU) of Northern California collectively filed a civil lawsuit Wednesday against the City and County of San Francisco and its police chief, alleging that the activist's rights were violated when a police officer warrantlessly searched his cellphone at the time of his arrest in January 2012.

Bob Offer-Westort of the Coalition on Homelessness, says in court documents that the suit stems from an incident where he was non-violently engaging in civil disobedience to protest a new city ordinance that made it illegal to camp in public places without permission. A spokesperson for the San Francisco Police Department said that the department does not comment on ongoing lawsuits.

The court documents, filed this week, charge San Francisco and its police department with violating Offer-Westort’s privacy, conducting an unlawful search and seizure, and violating his free speech under the United States Constitution and the California Constitution, among other allegations.

The ACLU claims that this is the first “civil suit in California to challenge warrantless cell phone searches at arrest.” In 2011, the California Supreme Court ruled in the case of People v. Diaz that arrestees’ phones can be searched without violating the United States Constitution.

“This suit brings a challenge under the California Constitution’s stronger guarantees of privacy and freedom from unreasonable search and seizure, as well as a challenge under the U.S. and California Constitutions’ guarantees of freedom of speech and association,” the ACLU wrote in a statement.

“Looking for text messages—how do you feel about that?”

On January 27, 2012, Offer-Westort pitched a tent in Jane Warner Plaza in the city’s Castro district. Inside that tent, he placed a sleeping bag, and he sat at the tent’s entrance with his mobile phone—an LG GU295, a slider phone—in his pants pocket. After some time, two San Francisco Police Department officers approached Offer-Westort and told him that his presence there violated the city’s penal code. The activist declined to move, and he was promptly arrested and taken to a police station.

After his arrest, but before his formal booking, the officer named in the documents as “Officer Chambers,” conducted a search of Offer-Westort’s phone. The plaintiff recounts what happened next in his court filing:

Offer-Westort was nervous about the police looking through his text messages because he had recently sent text message that included negative comments about a local politician and that he intended to relay exclusively to the message's recipient but otherwise to keep private; if this text message were made public it could adversely affect his ability to work with this politician and with other politicians. Offer-Westort was therefore extremely concerned about the government reading his private text message about [the] politician; Offer-Westort asked Officer Chambers what he was doing [and] Officer Chambers stated something to the effect of: “Looking for text messages—how do you feel about that?” Offer-Westort objected to the search, stating, "I don’t give you consent." Officer Chambers did not cease the search upon Offer-Westort’s objection, instead responding with statement to the effect of: “The California Supreme Court gives me the right after I arrest you.” Officer Chambers continued with his search of Offer-Westort's cell phone, reading many of Offer-Westons text messages and relaying their contents to him, including three text messages Offer-Westort had not yet read himself as they had been received after he was arrested; Officer Chambers then left Offer-Westort handcuffed in the waiting room and continued his search of Offer-Westort's cell phone. At least twice over the next two hours Offer-Weston could see Officer Chambers in other parts of the station either scrolling through his cell phone or holding his cell phone. In the course of the warrantless search of Offer-Westort's cell phone Officer Chambers read messages authored by individuals other than Offer-Westort who had not been arrested and messages that were unrelated to the crime for which Offer-Westort was arrested.

The City and County of San Francisco has yet to respond to the lawsuit.