hey @Maciek sorry for the late reply on this, been quite busy, hope you understand... you are spot on on this! I mean the irrevocably growing utxo set caused by spam. I don't know what I was thinking, probably I was addressing some other knots's gang argument that you didn't bring up. sorry about that. so, when it comes to polluted utxo set, this is actually my biggest concern, that imho, knots is not going to fix. The fake pub keys, without corresponding private keys, generated to smuggle arbitrary data can be indistinguishable from valid transaction keys. Of course there might be a need to put some data markers to tell where the arbitrary data is hidden, but those can be changed at any time, at zero cost and with the speed of light. How do knots want to combat this? You mentioned a PR created two years ago. Do you know the mechanics of this? How this PR could prevent from faking pub keys? I am very curious. Once a fake pub key enters a confirmed transaction, it will stay in the utxo set until the very last day of Bitcoin, which means forever. You said you are not going to argue with my B, but saying that we can prevent creating fake pub keys is a contradiction to my B. so, what am I missing here? Also, please don't tell me you don't like spam, there is no single bitcoiner that wants spam in Bitcoin, if they say otherwise, they are just trolling. We don't need to remind each other that spam is an unwanted thing. We don't need to bring this level of arguments together with why bitcoin is important when we talk about technical aspects of spam prevention. Imho, the question we need to answer is: is our time and energy worth fighting this, or better focus on other things and create incentives for other users of the Bitcoin network, so the need for spam diminishes naturally with ongoing Bitcoin adoption.