I remember declining a job offer (I had the contract to sign) long ago because one of the people I'd nominated as a reference contacted me and said "I legally can't answer the questions they've asked about you". Turns out their pro-forma reference questionnaire asked things like "Is this person punctual?", "what issues has this person had?". General dirt digging
If anybody were to answer that and the job offer got revoked, I could take that person to court for libel. Companies should know better than to ask anything but factual details in a reference.
So I turned it down stating that if they were so unprofessional around recruitment I wouldn't trust them to be a good professional employer if I worked for them.
This was 2005. It's not new.