I believe that if you can 'prove' that your resources are other than the person who has them posted or published elsewhere, you are safe. Technically, you will be personally guaranteeing that you did your research at X library and this is where the material came from. You can actually quote some of the published stuff that the person is screaming about copyright, if you give them credit for the source and don't copy it 'wholesale' so to speak. I've encountered the same dilema. I have a database with over 50,000 names. Every name that I 've posted into the database has a source listed. In many cases, I have more than one source. If you have more than one source, then any one singular source can't say you stole from them. I am not a lawyer, but this is my amateur impression. If anyone else knows better, I'd love to be corrected.