As far as I can see the ancestry.com website does not display data for "living" people, although how they determine who's alive is not clear. Are you referring to having identifying details of living people like own siblings in a genealogy program on a local machine?

I've looked just this morning at a friend's copy of FTM 16 and noticed that access to its internet features requires a login, and that in fact the password to your ancestry.com subscription works. However it asks for the email address associated with that account, not your user ID on ancestry.com, and can't access your genealogy data associated with that account. So authentication is using at least some of the same information but ancestry has quarantined the online data. It doesn't look all that expensive an extension that people are talking about, considering the cost of the subscription.

You mention: "Do you realize that Ancestry has rights to your data? Read the upload agreement. Is that what you want?" Quid pro quo, I imagine. I don't see genealogical data as all that sensitive. Additionally, ancestry.com's legal framework is that of the US and/or EU and both have privacy laws.

I'm not referring to backup onto Cd etc - that would be of a downloaded gedcom etc which is already possible. I'm talking about effectively initialising a local genealogy program with all the data you've already entered in the web interface. A large part of the whole exercise is how to transition from using only the web interface to using both it and a local program - without having to re-enter everything a second time. The gedcom-download-import route seems to lose lots of information, especially "timeline" event information in each individual person's record. That, and sources, are what I particularly want to preserve on import.