• by Wendy Davis , Yesterday

The prediction platform Kalshi allegedly violated users' privacy by disclosing certain financial information about them to Google and LinkedIn, a California resident alleges in a new class-action complaint.

"Despite reasonable expectations of privacy, defendant disclosed information regarding each bet," Stephen James alleges in a complaint quietly filed late last week in the U.S. District Court for the Southern District of California.

"These disclosures include communications that contain sensitive and confidential information," the complaint continues.

James adds that he has placed "numerous bets" on Kalshi's site this year, and didn't agree to share data about himself with Google or LinkedIn.

His complaint includes claims that Kalshi violated federal and California wiretapping laws.

A Kalshi spokesperson said the company "will defend against these claims vigorously."

"This is the latest in a trend of opportunistic plaintiffs bringing these types of cases -- it's a pattern that has swept across the industry with little regard for the facts," the spokesperson said, adding: "Kalshi takes customer privacy seriously and maintains strong measures to protect customer data."

As with numerous other recent lawsuits accusing web companies of privacy violations, the claims against Kalshi center on analytics tools allegedly embedded on Kalshi's website -- specifically, LinkedIn's Insight tag and Google Analytics.

James alleges that LinkedIn's embedded JavaScript code "sends secret instructions" to users' browsers, which then transmit data to LinkedIn that allow the company "to know the identities of specific individuals as well as their private financial information."

The complaint includes similar allegations regarding Google.

Google and LinkedIn were able "to profit from this information for targeted advertising purposes," he alleges.

It's not yet clear whether the complaint against Kalshi will gain traction, but several other companies have defeated similar lawsuits.

For instance, in 2024 the highest court in Massachusetts sided with hospitals in a lawsuit accusing them of violating that state's wiretap law by allegedly configuring their websites to transmit analytics data to Google and Meta, via Google Analytics and the Meta Pixel.

Late last year, a federal appellate court sided with Quest Diagnostics in a lawsuit claiming that it violated California's wiretap law by allegedly sharing website visitors' browsing data with Meta via its analytics pixel.

But judges have not uniformly dismissed comparable lawsuits. Earlier this year, for example, a federal judge rejected Capital One's bid to throw out privacy claims centered on allegations that it embedded tracking tools from outside companies on its website.