Can I find out what files are being stored on my hard drive?

When BTFS uploads a file to the network, the files are broken into blocks of max 256 KB size. As a host, you will only store a few blocks of a file. This way, no host can piece together any file from the blocks stored on their drive. Additionally, hosts are unable to view a file unless they happen to have all the blocks corresponding to a file, so it would be impossible for them to view even the partial file.