Those on the list do not have to be questioned. Only those willing to submit to questioning will be interrogated. I think they should be required to answer questions. But if they don't, authorities should monitor them and if they break the slightest law, they should be deported.
Dangerous times demand an aggressive response. I strongly suspect that the 19 hijackers of planes on Sept. 11 were only a vanguard of many other terrorists already in this country. Self-defense requires extraordinary means if we are to protect ourselves from another murderous assault.