Our iFolder instance has had a problem with data going missing for a while. Whole folders will suddenly become empty which is as much as problem as it sounds.

I don't know if it's something in iFolder that could be causing this or whether it is a user issue. Many of our iFolders have a large number of users sharing the data.

Is there a way to prevent users from deleting the data? I.E. can we give them read/write but not delete permissions?

It's difficult to determine the cause because the data is discovered missing and the users don't seem to know when it went missing, trying to get specific document names has been challenging also. We have implemented a more comprehensive/robust backup solution but that doesn't solve the issue.