From the whitepaper:

8. The user completes the captcha challenge and publishes his post and captcha challenge answer over pubsub.
9. The subplebbit owner’s client gets notified that the user published to his pubsub, the post is not ignored because it contains a correct captcha challenge answer.
10. The subplebbit owner’s client publishes a message over pubsub indicating that the captcha answer is correct or incorrect. Peers relaying too many messages with incorrect or no captcha answers get blocked to avoid DDOS of the pubsub.
11. The subplebbit owner’s client updates the content of his subplebbit’s public key-based addressing automatically

I may be misunderstanding how this protocol works, but at step 10 what prevents the owner from publishing the captcha answer as incorrect as a method of censorship based on the content of the post?

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When I was learning c#, I found the .Net framework tutorials available on freecodecamp to be good.

Also, using the Jetbrains Rider IDE (assuming this is for private non-commercial purposes, as per the terms of their free license) rather than VSCode or Visual Studio. VSCode is still lacking in features when it comes to c#, and Visual Studio probably makes more sense if you’re already accustomed to c# dev.