Anyone backing up to the cloud, please remember that it is not 100% safe, not by any means. Companies large and small have been known to take shortcuts; over-worked IT departments of all kinds have horrendous screw-ups; hardware fails everywhere; hackers and digital vandals are always trying to destroy or steal stuff (cough cough, Medibank, Optus); and possibly the biggest risk of all, companies go broke without the slightest warning.

In other words, the cloud is just another form of backup, subject to much the same risks as every other form. There is only one safe answer, and that is many different answers. If you are backing up one way (any way!) it is unsafe. Many copies in many different places stored in different ways is safe. Nothing else is.