NRC.nl reports (translated):
The website of the Amsterdam housing corporation Stadgenoot has recently been hacked. Private data was stolen from a maximum of 30,000 people who shared their data with the corporation. Stadgenoot informed the victims by email on Wednesday. According to a spokesperson, names, addresses, e-mail addresses and in some cases license plate numbers and indications of annual salaries have been stolen.
Read more on NRC.nl. If I am understanding translations of what I am reading on a few sites, it was their web host who got hacked.