Also, by the by, there is some interesting context about the author (Mike Hearn) and his recent activities that are not related to the topic of spam.
Warning: off-topic digression below.
Mike Hearn became one of the most visible Bitcoin core developers, working in that community for 5 years, until a well-publicized departure where he declared Bitcoin a failure[0].
He then joined R3CEV, a startup venture that is building a private blockchain platform for a consortium of 70 of the world's largest banks. Hearn's departure was criticized by members of the cryptocurrency community, such as Bram Cohen, who famously called his exit a "whiny ragequit" [1].
Regardless about how one feels about the internal politics of the bitcoin dev community, the R3 project is technically interesting (to me, at least) because it uses Kotlin [2], a JVM-based functional language, and also because it has some interesting design approaches that depart from the established bitcoin blockchain model [3].
I still think that private blockchain platforms have an uphill battle if they want to compete for developer attention with rapidly evolving broad-based platforms like Ethereum and Bitcoin, but the R3 Corda platform is nevertheless worth tracking.
[0] https://medium.com/@octskyward/the-resolution-of-the-bitcoin...
[1] https://medium.com/@bramcohen/whiny-ragequitting-cab164b1e88
[2] https://twitter.com/hhariri/status/790077263572299780
[3] https://gendal.me/2016/10/25/r3-corda-what-makes-it-differen...