At least the Bush administration will never go after radical political content, un-American ideas, liberal or socialist - or even Marxist and communist - thinkers and the like. All sorts of extreme left-wing, anarchist, anarcho-socialist and revolutionary ideas are, after all, protected by freedom of speech. I trust that the practice of Islam and the Muslim Umma in general are safe from prying eyes, too. This would all be consistent with the libertarian and liberal principles regarding free speech America tends to hold dear. Some sacrifices have to be made, of course. It would be a shame if radical militants or terrorists would be free to plan acts of insurgency or terror, though. Nobody wants to see the President assassinated by foreign activists.
Foreign agitators are another thing, though. Especially secularists and atheists. They're a kind of a grey area. European liberals in particular are a menace to national security and may seek to inspire all sorts of reformist, civil rights and liberal - even libertarian - agendas, even spread atheist propaganda. Surely they are radicals, they may even disagree with the US administration even though how it runs the country is no business of theirs. At least they don't have connections to Decembrists or other fringe groups, like Cubans, The American Communist Party, Neo-Spartacists, The Gay Agenda or The Elders of Zion, who, as we all know, are a threat to family values and have an international conspiracy involving The Black Panthers, The UCLA and maybe the Trilateral Commission. Its object, as we know, is to socialize/nationalize American property, bring about gay marriage and destroy Christianity with awesome Anarcho-Stalinist Gay Jihad of Frog-Eating European Doom powers which might or might not be related to the Flat-Earth Society and the Catholic Society of Jesus, the underground Trostskyite freemason press and Liberation Theology.