[GNUnet-developers] Plausible deniability challenge?

[anonymous1]

A question from a Freenet user:

One of the ways GNUnet improves on Freenet is that it allows persistent 
storage. However, since storage space is finite, it requires people to delete 
files from time to time.

If gnunet-delete uses a secret key to allow only the inserter of a file to 
remove it, can't the presence of that secret key on a user's hard drive be used 
to prove the user is the originator of that file?

I haven't been successful at finding much documentation on plausible 
deniability in GNUnet and the way insertions and deletions work. If I'm grossly 
misunderstanding something, please let me know.