It'd be nice to have some kind of public list where we could report companies that ghost, to warn other engineers to stay away.

You can't trust this because candidates do get petty when they get rejected and invent or omit details. That happens often on glassdoor.

Just like with any "crowdsourced" review site, I find value in the reviews, even if I don't, strictly, trust them.

Of particular value are multiple reviews that corroborate certain details, especially in the absence of reviews providing contradictory details.

At the very least, with something like "ghosting" during the interview process, it can help set expectations and inform behavior such as follow-up. For example, if interview reports complain of ghosting, I might still apply, but I wouldn't exert as much (if any) effort in soliciting a post-interview reply.

Just write up a review on glassdoor. Specifically calling them out for a crappy interview process. Or if you are really bold and bother with linkedin, make a post.

seems like the interviews portion of glassdoor would support that?

(caveats re trusting glassdoor, blah blah)