Pardon my ignorance, but how is it possible to track Bitcoin holders? I thought that it was really easy to create multiple Bitcoin addresses, so if a rich miner wanted to hide his holdings he could create a separate address for each transaction and he would in effect be untraceable right?
There is lots of other metadata to collect:
You can monitor which nodes received the transaction first. Edge nodes can get IP address of sender. Who are the transactions with? Amounts, quantity, and time of day/week/month could all provide correlation.
