A word of warning

Not to mention that it's not anonymous. People can analyze the blockchain and figure out who has how many coins, and where they've been spending them. And it doesn't help that major exchanges like coinbase have been sucking up to the feds since they were conceived.

Mining is an issue, but there is also an exchange issue that has been around since the beginning. It is why the value crashed down from over 1000 USD in 2014. The exchanges aren't always safe and they're handling tens of million dollars at any given point in time. They get hacked, and they are run by people who sometimes steal. In order for this to work properly, there needs to be a widespread adoption of decentralised exchanges. They exist, but the majority of volume is not being shifted on them.

The exchange also feeds the mining problem. If I make millions of dollars in transaction fees, I can afford to buy mining equipment, meaning I have an even stronger hold on the market.

https://www.theguardian.com/world/2013/oct/04/tor-attacks-nsa-users-online-anonymity

The same goes for any letters agency in the US since then. Don't rely on TOR for privacy for any activity that could be relevant for any letters agency, which is basically any activity.

I wouldn't say it has been compromised, but the design is flawed and there is no doubt it is partially compromised in the same way that the rest of the internet is.

Lets say you run some tor nodes, and I'm using them to connect to the network. If you're running the first node I connect to, you can see my IP, and that is all you can see. If you're running the last node I connect to, you can see the IP of the node I was connected to before yours and also the thing I'm looking at, like a website.

These two things alone are not enough because there are multiple points in between those two nodes, so even if you know my IP from the first connection, you won't be able to match it to the last node and be able to see that my IP is accessing whatever site it is.

But, if you happen to own all of the nodes in between, you can see everything. This is highly highly unlikely though. Say I am connected to a chain of nodes. You own the first and the last. Let's say you own the website I'm looking at. You can set something up so an identifier of some sort is sent back to me from the website I've just loaded, which will appear on all of the nodes you own and can be traced back to me.

This is the reason that it is recommended to not load javascript on websites over tor, because it is a lot easier to identify someone. An example of one of the ways this can be achieved is by using browser fingerprinting. The tor browser is designed to look like every other tor browser, making it difficult to use this method. However, if I write a simple script on my website to check the size of the browser window you're using, and I also own the exit node and entry node that you're using to connect to my site, I can tie a browser window size to your IP.

The best case scenario is that you're using the browser in the size that it opens in, in which case I won't be able to match you exactly and I can only cancel you down. In the worst case, you are using a unique window size and I know your IP plus the site you're on. This all seems very complex and time consuming, but this method has been used to catch people before. In fact, the creators of the tor browser now recommend that you do not alter the window size at all, even if you're making it full screen.