Brian Krebs reported that X (formerly known as Twitter) started automatically changing twitter.com links to x.com links. The problem is: (1) it changed any domain name that ended with “twitter.com,” and (2) it only changed the link’s appearance (anchortext), not the underlying URL. So if you were a clever phisher and registered fedetwitter.com, people would see the link as fedex.com, but it would send people to fedetwitter.com.
Thankfully, the problem has been fixed.