 Loic asks, how do lightning fees work? Are there fees only for opening and closing channels? Are lightning nodes really capable of censoring transactions? Great question, Loic. There are really two sets of fees you need to consider here. There are fees for opening and closing channels, but those are not lightning fees, but just bitcoin fees. In order to open a channel, you are creating a multi-sig address that is controlled by the two endpoints of the channel. That multi-sig address effectively requires funding, so you have to initially fund that channel. That is a transaction that you have to do on bitcoin, so you would have to pay one or two satoshis per byte for that transaction. It will cost you 20-25 cents in order to open a lightning channel. There is a mistake in the assumption that in order to use lightning, you have to open a channel for every payment, and then close that channel. That is not true, otherwise the whole system wouldn't really make sense. You only have to open a channel once, and then you can make many, many lightning transactions through that channel. You don't really have to close a channel. There is no deadline by which a channel has to be closed. You don't have to move your money back to the bitcoin blockchain, to a bitcoin wallet, from lightning. You can continue to just use it in a lightning wallet. As lightning gets more and more mature, and you can do more things with it, there is less and less reason to close a channel. There is also a number of innovations around that that can make it easier to, for example, open a channel while you are doing another transaction that you are already going to do, so that is called splicing, and closing a channel while you are doing another transaction, or opening multiple channels simultaneously in a single transaction. There are all kinds of tricks that are meant to reduce the number of fees you pay to open and close a channel. That is the bitcoin fees you pay for channels, but separate from that, when you make a lightning payment, and that payment is routed through multiple other nodes, as it should be, you are not supposed to have a payment channel directly to the person you are paying, you are supposed to have a payment channel into the network, and from there it is supposed to route your payments to the destination. Lightning fees are charged at each hop, as your lightning payment is routed between channels. Lightning fees are extremely low, so at the moment the average fee is in the thousands of a satoshi, and even people who are running routing nodes on lightning and routing payments by the thousands of payments are still making just a few dollars for their fees, so this is not a great source of income right now, but it is also not a great source of cost. Lightning fees are completely insignificant, the fees you will pay are so tiny, and in many cases you can route payments for free. Lightning fees are not a very big consideration when you are using a lightning wallet. To the third part of your question, are lightning nodes really capable of censoring transactions? In theory, yes. In practice, no. In theory, you could configure your lightning node to censor some types of transactions. In practice, however, part of the way routing works on lightning is that when you receive an incoming payment request, that you are routing across your node, you can't tell where it is going, and you can't tell where it came from. You know the node that sent it to you, the first hop before you, and you know the first hop afterwards, which is the node you need to send it to in routing, but you don't know the final destination, and you don't know the origin. You also don't know how long the routing path is. All the routing paths always appear to be 19 hops long, and you don't know which position in the routing you are in, so you don't know if you are first, second, or third hop in that route. That mechanism of onion routing ensures that you have no way of knowing who is paying who. All you can see is that the node before you asked you to pay a node after you, but you don't know if they're simply routing for someone else. In fact, most likely they are, just like you are, and they don't know where it came from either. They just see you as the next hop. So in terms of censoring transactions, on what basis would you censor transactions? You could just not route transactions at all. That's not really censorship. That's just you not making any lightning fees and not routing effectively. You might as well not run a node. Censoring transactions in terms of looking very carefully at which nodes you route to and which ones you don't, doesn't make any sense, because even if you say, I'm not going to send any payments to this node, someone can route a payment in a completely different route that doesn't involve that node, and it will get through. In fact, when a lightning wallet is looking for a route, it doesn't just find one route through the network, it finds several routes through the network, and then tries them in order of the least fee until it can get the payment through. Therefore, if you create censorship, lightning will route around it. The routing infrastructure is very similar to how the internet works, specifically the Tor network. It's an encrypted onion overlay route, which means that the old adage that the internet sees censorship as a routing problem and routes around it applies very much to lightning. You can't censor it because that's just seen as a failed route, and lightning will route around your censorship, and will be able to find a route around your censorship.