How did people discover the you are home accounts?

As the rumors about HS4 are getting louder and louder I’ve recently been thinking that it‘s possible that for his next album Harry is going to tease us with an instagram/twitter again. I wasn‘t a Harrie back when Harry‘s house was released so I was wondering, what was the process of all this teasing back then? When did people discover the accounts, how long did it took them, and how did they discover them? I‘d just like to be prepared 🤭