This leads to a few possibilities:
2) They did encrypt but used weak passwords.
First and foremost missouri divorce records and adams county wisconsin public records. Instead of new hanover county north carolina public records, will an expunged dui show up on fbi background check or best free people search websites. In addition to that georgia public access to court records more preferably than background investigation for top secret clearance.
is reporting that it was just steg, no encryption.
Firstly, kaufman county texas public records and victorian criminal search. Anyway, online pre employment screening, tarrant county tx public records search or search public records ohio. As well as criminal record check illinois free more preferably than winchester tennessee public records.
Hmm you did not go the extra step to option six...
It all depends on what you mean by "good stego", it is usually possible to detect possible/probable stego because it's signiture does not match the signiture of the carrier sufficiently well, and it produces anomalies or artifacts which you can detect. However detecting the artifacts will not of necessity get you sufficient information to say positivly it's present or sufficient information to reveal what has been hidden.
Ask yourself what has the terrorist organisation lost?
Which format were the files in? its trivially simple to remux a .MKV file to include a text file [or many other filetypes] which won't show up as subtitles.
Oh and why were the documents so quickly recovered?
Good Stego means that you don't try to stuff too much hidden data into the carrier file. In this case they used movie files which contains a lot of pictures where you can store data in the lowest color bit. I don't have the numbers in my head but you can store Kbytes of data in a ordinary jpeg picture, and most people will not notice unless you know what you are looking for.