> The code you reversed is used to protect many sites’ registration process including Google and many others. We are concerned that having your code and analysis publicly available will make it easier to build registration automation tools which will result in a surge of spam in all the services protected by this code and will affect negatively many Internet users.
> This is why we kindly ask you to temporarily remove it from GitHub so your work won’t be used for a malicious purpose which we believe was never your intended goal.
As I wasn't aware that the botguard was also used for this purpose (separately of ReCaptcha, in Gmail and other services) before publishing my code, I removed the GitHub repository for now. I'm sorry for honest security enthusiasts who didn't read the article, but I don't want to cause harm.
Google also proposed me to come visit them in their offices to discuss about my work.