Incitement to disaffection was a crime under Federation law.
In 2269, Montgomery Scott described the actions of one of Doctor Sevrin's followers, "one of those barefooted what do you call 'ems", as inciting his engineering crew to disaffect. Spock then cautioned Sevrin that he and his followers could be charged with incitement to disaffection if they persisted in swaying the crew of the USS Enterprise towards their quest for Eden, adding that, as criminals, they would not be allowed to colonize it. (TOS: "The Way to Eden")
Real incitement to disaffection laws generally pertain to seducing soldiers or law officers into not carrying out their duties or forsaking their allegiance.