Proscription is a high-voltage switch. Flip it and the whole circuit of speech and policing changes overnight. Since 5 July 2025, showing support for the group has been treated as a terrorism offence, and that makes ordinary activists step back even when they mean lawful protest. On 13 February 2026 the High Court said the decision was unlawful and disproportionate, but it also noted some actions could fall inside the Terrorism Act 2000 definition. That mixed finding is why ministers want an appeal and why campaigners call it a civil liberties win. The incentives are messy: government wants a deterrent headline, police want clear powers, courts want a principled line, and the public wants safety without panic. If the consequential hearing on 20 February changes the order, watch what happens to arrests and to the way other protest groups behave.