There are devices a high-level culture could produce that simply don't belong in the hands of incompetents of lower cultural evolution. The finest, and most civilized of tools can be made a menace ...
It's one thing to try to get away with what you believe to be a lie and be caught at it— and something different, and far worse sometimes, to find it isn't a lie ...
Although the Masquerade itself, as a necessary protection against non-telepaths, was not fully formulated until the late years of the Seventeenth Century, groups of telepaths-in-hiding existed long before that...