Every kid at that school wears the same uniform. Stand at the gate at eight in the morning and you cannot pick anyone out. Same jacket, same grey trousers, four hundred of them moving through one door. The uniform is doing exactly what it was bought to do. Then one kid walks through carrying a trumpet case. The uniform still works. The crowd is still four hundred strong. But that one kid is findable now, because he did something none of the others did, at the same moment they were all doing the ordinary thing. Here is the setup, and it matters for money. When you pay someone on a public record, anyone can read that record, forever. Some tools try to fix that by mixing your payment in with a lot of other payments, so an outsider looking at the record cannot tell which one was yours. The number of people you could be mistaken for has a name. It is called your anonymity set. The bigger that number, the better your cover. So people ask how many users a tool has. I would ask something narrower. Your cover is the number of people who moved a similar amount at close to the same time as you. That is a far smaller number than the user count, and it moves every hour. Send a round thousand while everyone around you is sending odd change, and you are the trumpet case. Move at four in the morning in a crowd that moves at noon, same result. Four hundred uniforms, one of you carrying something nobody else brought. Now the case against me, and it is a good one. Most people never do anything unusual. They send ordinary amounts at ordinary hours. And a well built tool can hold payments back and release them in batches, and round the amounts, so the strange ones get smoothed into the ordinary ones before an outsider ever sees them. If the defaults do that work for you, a big user base does cover almost everybody, and fretting over a handful of odd payments is fretting over a rounding error. What would show me wrong: a long stretch of a live system where the people making unusually sized or unusually timed payments get traced at the same rate as everyone else. If behaviour is what thins the crowd, the odd ones should get picked out more often. If they never do, then counting users was right the whole time. Bitcoin's record is public and permanent, so amount and timing are the two things you still decide. Worth knowing before you settle on how covered you are. if this changed how you count your cover, Zap ⚡