Millions of addresses available online after major Dutch data leak

Millions of addresses available online after major Dutch data leak

A major error at the Netherlands’ Cadastre, Land Registry and Mapping Agency (Kadaster) has resulted in the personal information and residential addresses of millions of homeowners in the Netherlands being freely available online, RTL Nieuws has reported. 

Addresses and data accessible to the public via Kadaster

As an official government agency, the Kadaster documents administrative and spatial data on properties in the Netherlands, collecting and registering information regarding purchase prices and ownership. This means that anyone who has bought a house in the Netherlands is listed in the Kadaster. 

While this information is typically only accessible to certain groups, such as lawyers and estate agents, research carried out by RTL Nieuws has revealed that a “serious leak” meant that, for years, all this sensitive data has been accessible to members of the public. Instead of enforcing tougher regulations for the creation of an official account in order to access this information, the Kadaster “does not verify identities”, making it “possible for anyone to create a professional account” in order to access private data.

The “leaky” security has allowed members of the public to enter an address and discover a property’s purchase price and the name of the owner, or to enter a name and find the address of a fellow citizen or resident

Experts blame Dutch government for security oversight

Talking to RTL Nieuws, Aleid Wolfsen, chairman of the Dutch Data Protection Authority, explained how this oversight poses “a great danger to threatened journalists, activists and politicians,” as well as anyone who “has to deal with an angry, stalking ex.” Cybersecurity expert Dave Maasland agreed, pointing out that “the leak can lead to life-threatening situations.”

Maasland has placed the blame firmly on the Dutch government. “They are offering a kind of Yellow Pages for criminals,” he said. "It is unacceptable that the government…does not take any action to properly assess the current risks.”

“Someone could suddenly appear on their doorstep to threaten them, or worse. We therefore immediately instructed the Land Registry to close this leak,” Wolfsen said. In response, a spokesperson for the Kadaster told RTL Nieuws that the level of security has been “significantly strengthened”.

Thumb image credit: Jarretera /

Victoria Séveno


Victoria Séveno

Victoria grew up in Amsterdam, before moving to the UK to study English and Related Literature at the University of York and completing her NCTJ course at the Press Association...

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