Actually Google temporarily shuts down the service as I've tried changing API keys/domains but received the same error

A lot of Google employees are reading HN and actively posting so no surprise. Did they at least contacted you to properly open a ticket now that they implicitely recognized the vulnerability? Otherwise very very dickish move as it solve nothing and you basically worked for free...

Nothing

And now if anybody from HN team is listnening. Can you explain why this thread is fastly slipping from the front page?

Currently it’s being devanced by articles that are olders, with less upvote and fewer comments. Can you guarantee that nobody is able manipulate ranking? It’s only a hunch, but it’s not the first time that I notice that google related "bad buzz" move away from main page slightly faster than other...

PS: I’ll gladly accept downvotes. But answers on why I’m wrong or paranoid would have been better

There appear to be quite a few flags on the article pushing it down. The ratio of upvotes to age compared to the rest of the front page is a strong indicator of this.

Also: lots of HN'ers work at google. It would be a nice rule if people were told to abstain from using their flagging privileges when the company they work at is the subject of a thread.

Thanks a lot for investigating. Otherwise I could’nt have excluded that it was only me being paranoid about that.

It looks like the situation has mostly corrected itself by now.

Power corrupts. Absolute power corrupts absolutely. Absolute power hates when it is challenged in any shape or form

It's probably because a lot of Google folks are on here - protecting their brand. Unfortunately that part isn't transparent, but its hopefully a minor issue.

HN has moderation, so some stories can be pushed back into the /New stack by staff, they can fall again if aren't liked by the community

Although I don't think this is some sort of conspiracy, HN front-page is curated content, ranking is not only based on votes.

Flags are a factor, and function as downvotes on articles but are much heavier weighted than upvotes.

Ho do I hack into google I'm a kid and I want to make it say giberish instead of Google

does anyone know?

That doesn't sound plausible; what sort of service would YOLO be if a popular website using it resulted in an API ban?