It's not that straightforward. It really would depend on the set-up of the individual themselves and where they want to keep their information. If it were accessible to something similar to a OneDrive, and they were to store their communications off of their device on that OneDrive and it would be accessible from any device they might want to access it from at a later date, that would be a good example. However, it's also possible that they could download those communications and keep them on their device, on a local drive within the device itself.
