Adding an Ancestry User to your tree
 

This has just appeared. I have no intention of doing this, but does it mean that a complete stranger could hijack your tree?

Do you have any say over the matter?

Do you mean the feature they are rolling out gradually to various members where you can mark one of your DNA matches as being a certain person in your tree, Phoenix? I haven't got that feature yet, but as far as I know, the other person will not know that you have done it.

Or do you mean making another Ancestry member an editor of your tree? That has been possible for a long time.

It seems to be inviting you to add the Ancestry member A ie a living person to your tree.

If you had invited another Ancestry member B to be an editor, they presumably could see A on the tree, even if A could not?

Presumably. Actually, I think person B would also have to be a viewer, collaborator, or manager of your DNA test to see which DNA matches you have added to your tree.

Ooh, I have got this feature now! I am going to have a play with it and see what it does.

Adding people doesn't seem to have affected how they show up on ThruLines yet, but maybe it takes a day or two for that to happen?

I think it takes 24 hours for ThruLines to catch up. I'm not really understanding the value of this feature..... I'd be interested in your opinion!

It doesn't seem to be very useful yet, Sue. I was hoping it would correct mistakes in ThruLines (for instance, where my cousin is shown as my half-cousin) but it doesn't seem to have any effect on ThruLines at the moment. Maybe they will make some changes in the future which will make it more useful though.

It just links your tree to your match. No one else knows you have added the link, not even people with access to the tree. So it is entirely safe.

Found this on FB from someone who asked ancestry

Well, I have viewing access to a relative's DNA test, and I can see which of their DNA matches they have added to their tree (I think their tree is a public one but also, I have been invited to it).