Bose is being sued in the US by a customer who claims the company secretly logged his user data through its Bose Connect app and sold it to third-party companies.
Kyle Zak filed suit in a federal court in Chicago on Tuesday, and is seeking a court injunction to stop Bose collecting user data, along with $5 million (£3.9 million) in damages.
The lawsuit claims the company demonstrated a “wholesale disregard” for its customers' privacy by using its headphone companion app to collect listening habit details and sell the information to other firms.
Bose is yet to comment on the claims.
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Christopher Dore, a lawyer representing Mr Zak and partner at law firm Edelson PC, told Reuters: "People put headphones on their head because they think it's private, but they can be giving out information they don't want to share."
Mr Zak claims in the suit that he paid $350 for Bose's QuietComfort 35 headphones before downloading the Bose Connect app on the company's suggestion to "get the most out of your headphones".
The app is used to control various features of the headphones, such as noise cancellation. But after providing his name, email address, and headphone serial number Mr Zak said he discovered "all available media information" was being sent from his smartphone to outside companies such as Segment.io.
As Reuters reports, Segment's website states the company will collect user data and "send it anywhere".
Legal papers filed by Mr Zak claim user data is also collected from various other Bose products, such as the SoundSport Wireless, Sound Sport Pulse Wireless, QuietControl 30, SoundLink Around-Ear Wireless Headphones II, and SoundLink Color II.
Mr Dore said Bose provided no indication of the data collection or its scope, adding that listening habit data offers "an incredible amount of insight" into customer identity and behaviour.
TrustedReviews has contacted Bose for comment.
Let us know what you think of the claims in the comments.