Corey Robin:

Because the rhetoric of security is one of universality and neutrality while the reality is one of conflict and division, state officials and elites have every motivation, and justification, to suppress heterodox and dissenting definitions of security. And so they have, as Hobbes predicted they could and would. But because a neutral, universal definition of security is impossible to achieve in practice, repression for the sake of security must be necessarily selective: only certain groups or certain kinds of dissent will be targeted. The question then becomes: which groups, which dissent?

Because government officials are themselves connected with particular constituencies in society — often the most powerful — they will seldom suppress challenges to security that come from the powerful; instead they will target the powerless and the marginal, particularly if the powerless are mobilizing to threaten the powerful. So the US government during WWI made it illegal to urge people, like the Socialists, not to buy war bonds — but it did allow a Wall Street adviser to counsel his client not to make a bad investment.