First thing I thought of too. If you've acquired a company, you'll need to plan on keeping the old domain names for a long time, if not indefinitely. Anyone who can later re-register that domain will now own any email sent there and any other network traffic as well.

Agreed. For example NeXT was bought by Apple in 1997 yet next.com is still owned by Apple all this time later.

No no! That's gotta be Ghomainjacking, two buzzwords in one AND ghosts are waaay spookier! Phantoms evoke too much imagery of incels in masks, singing on boats.

I was also trying to allude to Saint-Domingue, the French colony which France woke up one day to realize it no longer had and "sans domain", which are way too nerdy. Let's go with yours

Ghomainjacking but it's pronounced fimainjacking using the gho from ghoti because it's in the class of phishing attacks using a collision you didn't realize was possible

If you ditch your twitter account and someone else adopts it and poses as you, you can only throw a tantrum. Beware for these twantrum attacks.

I thought Twitter famously doesn't allow reallocation of old usernames?

In fact, that's how you delete your old tweets: rename old account to a new username, register the old username, delete the renamed account.

https://help.twitter.com/en/using-twitter/delete-tweets

See "How to delete multiple Tweets".

As bad as it sounds.

After NPR said they weren't going to post anymore because Musk decided to label them as "State Controlled Media" he made a point of saying, "OK, then we'll give your username to someone else after it expires in a month (apparently not posting for a month now expires accounts?)"

They allow it, I closed my account and days later some bot had already taken over my old username.