a government's "just powers are derived from the consent of the governed". If people consent to a limited form of government, based on the doctrine of enumerated powers, and a Bill of Rights that restrains government, this government is not tyrannical. But as the Declaration also says, when a government fails to secure our unalienable rights, the people have the right to abolish it.
The real threat to the liberties of anarchists and those who believe in legitimate representative government as described above, is fascism. Lets all work together and defeat fascism and then we can debate which system affords the most freedom within a moral framework. For possible solutions to defeat fascism, check out this post.
http://www.dailypaul.com/277342 (Rand Paul: One person can make a difference)
http://www.standupforyourrights.me/?p=1264 (Resist gun control)