Is DropBox Decrypt something we need to worry about?

Aside from probably being a good idea to look at a local alternative which I saw mentioned on here to day or yesterday, I am curious, is this something we need to be concerned about?

http://www.magnetforensics.com/decrypting-the-dropbox-filecache-dbx-file-new-free-tool/

I was looking to find out what the files were, why they are so large, do they need to be backed up, etc. And then, ran into a way to decrypt them.

Suggestions and opinions?