Protecting against massive user error

Hi, I have been using a DS1821+ with 4x16Tb drives in a Raid 6 configuration on a single volume for about 6 months now. Everything has been perfect. This morning I woke up to a big problem - all my files were missing from one of the shared folders I have set up.

Everything seems to be working fine. No hardware errors or failures and all other shared folders are fine. I later discovered that at some point in the last 24 hours all my files had been moved to recycling bin so it looks like some kind of user error or manual deletion of the files. I am the only user so all I can think is I made some sort of mistake. This mistake shot through many of my layers of backup and I had to rely on my snapshots to restore. Thanks to Space Rex for the setup guides as this has saved my bacon!

Are ‘snapshots’ the general protection for this kind of issue? Or is there some other way to guard against it? Is there any sort of notification/verification that can be set up that looks for unusual activity? Kind of like setting a limit to transactions on a Credit card?

Does anyone have any recommendations or considerations?