Antivaxers frequently object to the use of fetal cell lines to manufacture vaccines on "moral" grounds. Über-quack Joe Mercola lays down some astonishingly bad moral arguments based on pseudoscience.
Did you know that vaccine pioneer Maurice Hilleman admitted that contaminating SV40 virus in early batches of oral polio causes cancer? That's because he didn't, although antivaxers keep claiming that he did and that SV40 from early batches of polio vaccine cause cancer. It almost certainly doesn't.