Researchers from Germany’s RWTH Aachen University have found hundreds links to illicit materials in Bitcoin’s blockchain. This was announced at the Financial Cryptography and Data Security conference held on the Caribbean island of Curacao.

The researchers studied near 1,600 files stored in the blockchain and found eight files with sexual content. Five files contain “mildly pornographic content”, while the three ones related to materials forbidden by law in 112 countries. These files contain a child abuse image and 274 links to pornography involving minors.

The researchers believe that the problem they identified can make the usage of blockchain unlawful. They note that a users who stores blockchain data in his system is unwittingly responsible for any content added to the blockchain even without his knowledge.

The researchers’ paper has drawn a lot of media attention, but it is still unclear exactly how much harm to blockchain industry it will cause.