In 2014, Amazon applied for a patent that would help de-anonymize crypto currency transactions and then sell that information to law enforcement and government agencies. Although Bitcoin was never meant to be totally private, the patent looks to remove almost all levels of anonymity from crypto currency transactions if possible.
The patent explains a “streaming digital marketplace” where data points form different sources are used to pinpoint users identities. Below is a quote from the patent application.
One example is a data stream that publishes or includes global bitcoin transactions (or any crypto currency transaction). These transactions are completely visible to each participant in the network. The raw transaction data may have little meaning to a customer unless the customer has a way to correlate various elements of the stream with other useful data. For example, a group of electronic or internet retailers who accept bitcoin transactions may have a shipping address that may correlate with the bitcoin address. The electronic retailers may combine the shipping address with the bitcoin transaction data to create correlated data and republish the combined data as a combined data stream. A group of telecommunications providers may subscribe downstream to the combined data stream and be able to correlate the IP (Internet Protocol) addresses of the transactions to countries of origin. Government agencies may be able to subscribe downstream and correlate tax transaction data to help identify transaction participants.