For one thing, I simply do not buy the Hollywood-inspired fantasy that evil government agents frame up some walking innocence just for the heck of it. I am much more inclined to assume some sort of rationality on the part of the people with whom I disagree - I thus find quite probable that the government must have had some bona fide reason to detain Mr. Padilla (whether they reveal that reason is another story).
There is a good reason to believe that the "government" genuinely tries to prevent terror attacks rather than simply rounding up innocent victims. If not anything else, such attacks are likely to create chaos and instability that will likely undermine the current administration - so they have a good incentive to protect their own asses by protecting the public.
As to Justin's assertion that this is a "trail balloon" to do the same to other US citizens - I've been too long hanging out in various dissident circles to fall for this canard. The founding myth of most dissident groups is that the government and its agents are after them and will use every trick available to get them. That gives the dissidents a sense of self-importance. In reality, however, there is no reason to belive that left-wing insurgency is threatening to the establishment that they use terrorism as a pretext to establish a police state to protect themselves. If not anything else, establishing such a police state would pose too big of a transaction cost that would cut into the bottom line of too many businesses. That is why the Soviets & Co, dismantled their police states - they were too costly to maintain, and still did not produce the advertised results.
I also think that counsels like "we should change our foreign policy, withdraw our support for Israel, eliminate disparity in wealth and eradicate other root causes of terrorism" belong to the same category as finding the meaning of life. Yes, it would be so nice if we all lived in peace, loved each other, held hands .... oh well, let me pass the bong.
The history has shown that liberal democracies are quite resistant to communist revolutions, but fell when attacked by fascist goons bankrolled by plutocracies. I was hoping for more realistic, down to earth answers how to avert such threat without giving up a democracy to Ashcrofts, Hoovers, or Hitlers.
wojtek