You are correct. It was many years ago a friend of mine who was running a blog in Britain had a run-in with Hizb-ut-Tahrir. This was the last in a series of threads on the subject. Note that this was written in 2006, and despite demands from Pakistan to ban the group
"Home Office lawyers, the Foreign Office and representatives of the Association of Chief of Police Officers have quietly lobbied against outlawing the group and have, for now won the argument. Surrendering we will go