I thought voter records were private and only candidates could have access to them for canvasing and mailing? If a candidate shares voter records then they are violating the law. At least that's my understanding. Can someone enlightenment me how his voting information is public domain?

I thought voter records were private and only candidate could have access to them for canvasing and mailing? If a candidate shares voter records then they are violating the law. At least that's my understand. Can someone enlightenment how his voting information is public domain?