“Personal Cloud” has been defined by usage as a person’s own slice of the world wide cloud.
If a network administrator ran a family VPN on a private basis, he would be able to control the family’s own data and backups, and this would become his children’s “personal cloud,” in a different use of the term.
Instead of having an Amazon Cloud drive, an Ubuntu Cloud drive, a Google Cloud drive, a Microsoft Skydrive and keeping some crucial data in a Dropbox account, these commercial accounts would become non-essential luxuries, and crucial private data, such as health records and intellectual property work product, would be stored on the home server, password protected on an ad hoc VPN.
It should be possible to configure a VPN on a “Live” type CD, such that almost anyone could employ a family VPN. This would be weak in the area of security updates, but it would also benefit from the fact that re-booting would expunge all virus exploits, with intruders starting over from scratch.
“Profiles,” would necessarily be separated, and possibly encrypted. The Shamir Secret Sharing Scheme would be an alternative to fiat root authority, to accommodate the privacy rights of adults. It provides for a password to be apportioned such that a quorum of individuals is required for access, but does not discriminate as to whom the individuals must be.
The mechanics both of profile security AND user authentication (for data assurance) might be demanding, but could be well done.
If the server were required to be “down” for backups, it would simplify questions about network pilfering whilst backing up, and obviate specific “versioning” questions.
In closing, controlling personal data and backups would be the purpose. If an amateur administrator failed to maintain backups, the entire scheme would become a liability. As such, a scheduled backup requirement (nag) would be self-consistent within the package.