> search engines treat links to your site as a massive signal of relevance and trust

I am admittedly a bit distant from SEO. The above is not true and hasn't been true for a long time.

Haunted is a weird way to call them, these are stigmatized domains.

I feel like this should be the registrar's responsibility. Least they could do is give a disclaimer and/or a heavy discount.

The domain could also have been used to run spam email campaigns, meaning that it is blacklisted by email servers

A risk that’s easy to overlook until it bites you

sounds like the makings of a business service

Also be careful connecting new domains to cloudflare. It has a habit of adding old info from presumably a previous owner.

Managed to get a takedown notice thanks to that idiotic "feature" while not even aware the domain is serving anything

that is amazing

Yet another valuable use for the WayBack Machine, glad it got a mention.