So George Osborne is now a terrorist then?
In its broadest sense, terrorism is any act designed to cause terror, so by suggesting that IS is planning an attack is in a narrower sense, terrorism. Especially as it can be understood to feature a political objective.
This constant scaremongering is pretty pathetic, I doubt that enough zealots have the ability to hack the UK. And surely if they went down the road of hiring skilled attackers then they would presumably have to put themselves to death immediately for paying for this foreign workforce. It should also be worth pointing out that when it comes to terrorism and the UK it is not very effective. During the London bombings on 7/7 there was a range of emotions, but the resounding emotion was akin to mild ambivalence. And that will never do!