Depends on the type of fingerprinting used. The example I mentioned with the invisible pattern yes but if the fingerprinting is done via other means such as rep

Depends on the type of fingerprinting used. The example I mentioned with the invisible pattern yes but if the fingerprinting is done via other means such as replacing some words on a post with synonyms for each user in such a way that each has a unique combination of words it wouldn't work. Generally speaking in these scenarios you don't want to grab anything directly from the source, just relay what you saw and write it down in your own words. Even then it has to be handled carefully (how many other people got this information? Are the details I'm seeing slightly incorrect in order to filter out who leaked this?) Also take into account that you can be caught just by repeated "A/B testing" of sorts: half the population gets informed that at 19:05 some operation is taking place, the other half that the op is taking place at 19:10. The next day they do the same but using different groups, if you have access to the data that is being leaked you can track down who is leaking it like that after a few iterations.