One of the plaintiffs was a journalist from Azerbaijan (https://en.wikipedia.org/wiki/Khadija_Ismayilov https://en.wikipedia.org/wiki/Khadija_Ismayilov). While

One of the plaintiffs was a journalist from Azerbaijan (https://en.wikipedia.org/wiki/Khadija_Ismayilov https://en.wikipedia.org/wiki/Khadija_Ismayilov). While it's not likely that the BND would share information about them directly with the government of Azerbaijan, the fear was that it would be shared with other services, which might take fewer precautions when passing it on. It could also leak, either accidentally or as a result of other countries' spying efforts.