Only some tale Zuckerberg's company censored (4)
I believe the answer is:
sole
'only' is the definition.
(synonyms)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for sole that I've seen before include "A lone sort of fish - lose it" , "Exclusive class of fish" , "Unique" , "Fish - alone" , "fish in the sea!" .)