I understand your concerns about security.
I will consider an option to encrypt the database.
For now, save the database to a Truecrypt volume (or other encrypted volume).
You can set the database location in Tools -> Options -> Indexes -> Database location.
Please note that while Everything is running, any app can query Everything for a list of results via
IPC, (or ListView Messages in the next release).
I'll look into an option to disabling these for the next release.
The Everything service can also be used to index a NTFS volume by any app.
For the best security use folder indexing, don't run Everything as an admin and disable the Everything service.
With folder indexing Everything can only see files and folders that any other app can see.