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Zuckerberg’s ‘Twitter killer’ Threads hits 70m sign-ups in two days
(www.theguardian.com)
This is a most excellent place for technology news and articles.
This will give you a good idea of which Mastodon instances will federate with Threads:
https://fedipact.veganism.social/
Just create an account at one of the instances that will federate and you're all set.