Please describe how you lost it.
What you did before? Any steps to reproduce?
Did you just removed them manually or is it system failure?
By saying User Data - you mean records in the Users table or what exactly?
We are checking our backups. Meanwhile your application is not secure. Any one with application id and apikey can remove all your data. Read following doc about security https://backendless.com/docs/rest/data_security.html
Are you sure it happened exactly today?
The graph above shows that removal requests occurred in portions throughout January. If you count the number of all removal requests for January, you will get 200+.
Does this mean that at the beginning of January you had 400+ users? Because if yesterday there were 200+, they are “gone somewhere”, and also add ~ 200 removed users via Android during January, we will get 400+ users at the beginning of January.