Everything is both legal and illegal until a lawsuit happens. Then it collapses depending a little bit on the facts and mostly on who has the better lawyers.
I suspect Nitter's first round with lawyers pointed out that scraping is legal, but now they have been threatened with something else than scraping - Elon claims something else the way Nitter runs is illegal, such as the use of fake accounts to circumvent an access control device (DMCA 1201).
I suspect Nitter's first round with lawyers pointed out that scraping is legal, but now they have been threatened with something else than scraping - Elon claims something else the way Nitter runs is illegal, such as the use of fake accounts to circumvent an access control device (DMCA 1201).