how do we know where and how bitcoin transactions can be tracked?
it's not possibly to know simply from looking at a single transaction. but if you look for patterns in the entire blockchain, and run spy nodes on the Bitcoin network, you can find out reliably who might own which addresses.
various special transaction types can be used to make the "might" part less reliable. NOT including "mixer" websites, where you basically tell the website everything and expect them not to sell that information on to others.
When I went on to read more, I discovered two things: Dash and Monero.
these privacy coins are trade-offs on the whole cryptocurrency concept, don't expect:
- speed
- low costs
- scalability
- resilience
...from those coins. maybe it's possible to get some kind of improvement of these properties in comparison to their balance in bitcoin, but it is a balance (famously observed in a phenomenon named "Zookoo's triangle")
