Very dubious
Claims about the dangerous new world that we live in need to be treated with extreme skepticism. There has only been one terrorist attack in Australia, and that was the Sydney Hilton Bombing which was almost certainly a botched but ultimately successful attempt by ASIO and special branches to obtain more funding. Claims to have prevented attacks also needed to be treated with skepticism.
Giving blank cheques to the security forces is potentially far more dangerous than a few terrorists. That is not to say that there are no bad/crazy Muslims out there, but the worst that they can do is kill a very few people. The security forces can be far more dangerous.
Perhaps the nastiest, most unnecessary and least commented aspects are the new cimes against any whistleblowers.