Better to arrest them, put them in court, and imprison those that are guilty for 10 years or more for terrorism.

EDIT: Or revoke their citizenship and deport them to Marxist countries in South America or Sub-Saharan Africa. Not nice to those countries, but generally fits much better with the systems there.

Better to arrest them, put them in court, and imprison those that are guilty for 10 years or more for terrorism.