I would go even further: Always have a local backup of anything on the Internet that is important to you, whether you made it or not, unless you know there are
many other accessible versions of it for redundancy. You never know when a large company will delete it without notice.
(Is this feasible? Perhaps not, but given how cheap storage is, if this could be even semi-automated, it would easily save a lot of heartache for some at many points in their life, especially in the worst cases of things like their Google accounts being banned)