Why do I find fictitious people listed in my 10th century and earlier ancestry on many different sites?
We believe that most people are doing their best to enter correct information into Family Tree. The majority of our guests are not experts and sometimes make assumptions that are incorrect. That is why sources are so important. They can document correct information. Reason statements are also important. When adding or editing information, there is a box that say "Reason this Information is Correct". This is especially important when you add information that you are making assumptions about.
Unfortunately, there are people out there who mess with our site. If you think you have a strong case of abuse, you can report it.
As far as other sites, such as Ancestry or any other site, we have no say what is entered on their sites. FamilySearch's purpose is to create one big family tree. In FamilySearch we hope people will work together to create an accurate tree. Other sites allow individuals to create their own family tree. People may enter what ever they want, whether it is correct or not.
We hope guest such as yourself will correct errors and document the corrections with sources.