If you're not informed about this organization, you should be. The Weekly Standard has a helpful primer. Money quote:
How worried should the West be about the expansion of this not directly violent group, yet whose alumni include al Qaeda's notorious Khalid Sheikh Mohammed and Abu Musab al Zarqawi? Very worried, argues Maajid Nawaz, a former leader and recruiter for HT in Britain, the organization's headquarters. As Nawaz explained this month to the New York Times, "Hizb ut-Tahrir spearheaded the radicalization of the 1990s and cultivated an atmosphere of anger. . . . Buried in the literature is an ideology that inevitably leads to violence." Hudson Institute scholar Zeyno Baran put it best: "While HT as an organization does not engage in terrorist activities, it has become the vanguard of the radical Islamist ideology that encourages its followers to commit terrorist acts. . . . HT today serves as a de facto conveyor belt for terrorists."
Here's a propaganda YouTube made by HT cited in the article. It's long and full of untruth: