By default, DNA Matches with your DNA kit or any of the kits you manage, can view and download information about shared segments. This information may help DNA Matches understand how they are related to you.
If you prefer to prevent other users who share their DNA segments from viewing and downloading the details of shared segments (position and size), please do as follows:
1. Log into your family site
2. Click on your name in the upper right corner of the Home page and go to “My Privacy”:
3. On “My privacy” page, click on “My DNA preferences” on the left-hand side:
4. Uncheck the box “Allow DNA Matches to view shared DNA segments and download shared DNA segment data”:
Further reading: What are the privacy options for my DNA data?