No, it's not that. It's that it may very well be possible to trace this conversation back to a single person and that could easily jeopardize that persons employment.
We begin therefore where they are determined not to end, with the question whether any form of democratic self-government, anywhere, is consistent with the kind of massive, pervasive, surveillance into which the Unites States government has led not only us but the world.
This should not actually be a complicated inquiry.
(The difference here being that in one case the government is the judge/jury/executioner and in the other it is the realm of public opinion.)