See Nissan Motors v Nissan Computers. Companies could simply email their registrar and say someone is squatting on their domain and registrars would acquiesce. Nissan Computers set the legal meaning of squatting which pretty much ended that practice.

Before that you were much better off using a registrar with a known dispute process (verisign) or in a jurisdiction which required a legal precedent (German registrar joker.com leapfrogged into stardom during this time)

Also the process of locking domains came out of these actions

In the 90s domain registration was all handled through email. You emailed from an approved address, with a specific format, to change anything about the registration. This included where your name servers were.

Made self-hosting interesting when your home IP changed, or you moved, and that was where you hosted your DNS and email.

itch.io was recently taken down because an AI lawyer was fired of sending DMCA complaints to the right place and decided to send one to the registrar instead.