The Federation of German Consumer Organizations (VZBZ) has filed suit against WhatsApp in the Berlin regional court, alleging that the company collects and stores data illegally and passes it on to Facebook, the federation said Monday.
The policy changes have also landed WhatsApp in hot water elsewhere.
Within days, privacy campaigners including the Electronic Privacy Information Center and the Center for Digital Democracy complained to the U.S. Federal Trade Commission, accusing the companies of unfair and deceptive trade practices.
The city of Hamburg was first to rule against the companies, ordering Facebook in September to stop collecting data about WhatsApp users and to delete any data it had already gathered.
In October, European Union privacy watchdogs asked the companies to end the data transfers while they investigated whether they needed additional user consent to comply with EU privacy laws.
The following month, the U.K.'s Information Commissioner said the company had agreed to stop the data sharing until it had obtained users' consent.
There's even concern that the data transfer may have breached antitrust law. In December the European Commission said it was investigating concerns that Facebook had intentionally or negligently submitted incorrect or misleading information to antitrust regulators in the run-up to its acquisition of WhatsApp. Back then, the company told regulators that the phone number matching now being done could not be performed reliably. If the Commission concludes regulators were misled, it could fine the company 1 percent of worldwide revenue.