Mountainview, California—Union activists marched through a tree-lined hilltop plaza at Google’s Mountainview headquarters Thursday afternoon, chanting, “No Union, No Peace!” Outside Google’s tall glass buildings, a Service Employees International Union (SEIU) official joined subcontracted Google security guard Manny Cardenas in asking a Google representative for an audience with company CEO Larry Page. After being rebuffed, they left the staffer with a letter condemning the treatment of the campus’ subcontracted security workers, which they charged contradicts the tech giant’s “Don’t Be Evil” motto.

“People use the phrase Google-y, basically to mean that it’s ethical,” South Bay Labor Council Executive Director Ben Field told the assembled crowd after the letter was delivered. “Well, I’m here to tell you—and all of the employees at Google—that SIS is not Google-y.”

SIS stands for Security Industry Specialists, a California-based security firm contracted by Google. The petition delivery was SEIU’s latest effort by to hold Google to account for the working conditions of SIS security guards on Google’s Silicon Valley campus. SEIU alleges that, unlike a previous Google contractor, SIS employs most of its workers as part-timers who can’t get enough hours to qualify for health insurance or sick days. SIS has also been sued by employees for alleged break violations and gender and sexual orientation harassment.

The crowd of about a hundred protesters included attendees bused in from the Netroots Nation conference and members of SEIU and other labor groups like OUR Walmart, but only a single SIS employee: Manny Cardenas. Organizers said that other SIS employees were too scared to go public.

Cardenas, 24, told The Nation that a lack of hours at SIS has left him to rely on his parents’ health plan to insure himself, and on Medicaid to insure his daughter. “I didn’t feel that was right,” said Cardenas. According to Cardenas, employees are left waiting for a text message or phone call from management each week to find out whether they’ll be working; he said he’s shown up for a scheduled shift only to discover that the company decided to give it to a more favored employee instead. According to SEIU, Cardenas hadn’t been offered any shifts since February—up until the company offered him work for the day of the protest.

SEIU’s campaign targeting Google is one of an array of labor efforts to organize workers through pressure at multiple points along the supply chain. Such efforts have taken on increasing urgency for organized labor as the rise of subcontracting has left more workers asking, “Who’s the boss?” While increasing numbers of workers are subject to the business model of a company that’s not the one actually signing their paycheck, US labor law specifically limits workers’ ability to spread labor struggles from their direct employer to other companies in the supply chain. (The Taft-Hartley Act restricts unions’ ability to stage what scholars call “secondary strikes” and “secondary picketing”—“secondary” meaning actions against a target that’s not the legal employer).

And while US labor law promises workers the chance to win collective bargaining with their employer, that’s worth little if the company that hired that employer retaliates by severing the contract. Thus, unions increasingly train their firepower on name-brand companies that hire contractors—who are also more vulnerable to public pressure—rather than on the contractors themselves. Through efforts like SEIU’s Justice for Janitors campaign, which pressured building owners in order to win union recognition from the janitorial companies they contracted, unions have sought ways to squeeze the contractors’ bosses without breaking the law. “The majority of our work in Justice for Janitors,” campaign architect Stephen Lerner told me last year, “was trying to figure out how to negotiate around the secondary boycott laws.”

Cardenas told The Nation that Google could change his job if it chose to: “Ultimately, they have all the responsibility, because they’re the ones that are paying SIS and contracting them. So it’s their decision to have them or not.”

Google and SIS did not respond to requests for comment. On a “Union Facts” page on its website, SIS accuses SEIU of “harassing tactics” and “lies and deceit” as part of a three-year “unsuccessful attempt to convince SIS employees to join their union.” The SIS page includes an employee’s resignation letter that cited “Outside Union Harrasment” [sic] (along with “Medical, Eldercare” and “Other Issues”) as a reason for quitting. It also links to information regarding an SEIU official’s corruption conviction, and a National Labor Relations Board complaint regarding alleged intimidation by SEIU in an election against the rival National Union of Healthcare Workers.

SEIU alleges SIS is playing dirty. In a charge filed with the NLRB, the union accused SIS of sending a supervisor to spy on a union meeting. In a September 2012 response letter, a regional NLRB director said that, based on the agency’s investigation, “it appears that your charge may have merit,” but that the NLRB intended to conditionally dismiss the charge because “the conduct at issue here is isolated,” and there were not other current or recent “meritorious allegations” against SIS.

Cardenas’s SEIU activism predates his time at SIS—he was also involved in trying to win union recognition at the previous security company he worked for. In both cases, he said, it’s been a struggle to get traction with co-workers. After coming to SIS last year, he said, “When I mentioned the union to one of my co-workers, he told me to not talk about the union because they’re real strict about that, and they don’t like people talking about that.” According to Cardenas, his co-worker warned him that the company could retaliate against him by cutting his hours.

Since that conversation, Cardenas said he’s been talking to co-workers about working conditions rather than mentioning the word “union.” He said he believes some of his co-workers would like to have a union, based on their complaints about the job. However, he told The Nation, “The last union meeting that we were at, I didn’t see any Google workers except myself. Every time the union goes to try to talk to the workers, they’re told to leave and stuff. So it’s been a challenge.”

While Silicon Valley is popularly associated with tech titans and start-up millionaires, SEIU notes that the region’s wealth coexists with stark poverty. The letter delivered to Google today notes that the region has reached a ten-year high in food stamp participation, and seen a 20 percent increase in homelessness over the past two years. “The problem is not unemployment,” the letter states, but rather that “many people who are working for a living are not making a living.” The letter’s signatories, who include leaders from the local NAACP, labor council and city council, urge Google to “find a more responsible security contractor” than SIS.

Asked about Google’s response to his request to deliver the letter to Larry Page, Cardenas answered, “It’s not what we wanted.” He told The Nation that he planned to try telling some co-workers about the day’s protest. As for how they’d respond, he said, “hopefully positively. And join us.”

Striking Walmart workers are gaining momentum. Earlier this month, they went all the way to Arkansas to protest at the company's shareholder meeting.