According to a new report from Bloomberg Technology, Amazon is paying people to listen to Alexa recordings.

Amazon’s Echo device helps users answer questions, find information online and use digital services by directing AI assistant Alexa through voice commands. The assumption is that those conversations between Alexa and users are kept private.

However, according to the report, thousands of Amazon employees (including some contractors) are tasked with listening to conversations, transcribing and annotating them, and then feeding them back “into the software as part of an effort to eliminate gaps in Alexa’s understanding of human speech and help it better respond to commands.”

The workers reportedly sign nondisclosure agreements that prevent them from discussing the program.

Some of what these Amazon workers heard—and how they handled it—is concerning. Two workers told Bloomberg they heard what they thought was a sexual assault. Though the company has procedures for what to do when they hear something distressing, in this case “they were told it wasn’t Amazon’s job to interfere.”

In a statement in response to the piece, Amazon said (in part), “We only annotate an extremely small sample of Alexa voice recordings in order [to] improve the customer experience … We have strict technical and operational safeguards, and have a zero tolerance policy for the abuse of our system. Employees do not have direct access to information that can identify the person or account as part of this workflow. All information is treated with high confidentiality and we use multi-factor authentication to restrict access, service encryption and audits of our control environment to protect it.”

You can read the full report here.