Odd that a guy so tech savvy would not have obfuscated such illegal content especially considering that such tech and tools are free like OpenPuff and or that he created such tools
for the CIA.
1) Encryption of files
2) Hide encrypted files in other files
3) Repeat steps 1 and 2 as desired
4) Upload files to file sharing service and zero write hard drive on which the files were created
Regardless - Josh will more than likely be going to prison.