After recent attacks several voices have suggested the use of internment (detention with trial); in part citing the volume of suspects (3-23k), the lack of resources and evidence for criminal proceedings.

This article 'Scrapping human rights is as great a threat to democracy as terrorism' reviews the history - mainly its use in Northern Ireland (1971-1975, it had been used in an earlier campaign by the Irish Republic) - and wider political implications.
Link:https://www.opendemocracy.net/uk/jul...ism-democracy?

I am a pessimist that politicians will use internment, probably under a supposedly more subtle title, if there is a series of successful attacks with high casualties - to be "seen to do something" and avoid a public backlash.