I have found the passport one on FB and 15 people have made comments about it, in addition to the 166 by GN users. As a member of FB there is nothing to stop me adding my comment on individual GNetters and saying 'I think x is talking utter rubbish' or 'I agree with the sensible comment from y'. I wouldn't because x and y probably won't see it- they don't realise that all of FB can read it! Or they are under the impression they are not on FB because they don't have an account.
Wicked Little Letters? (funny film of a long-forgotten case)