Unsurprisingly, this law is completely impractical and ultra dangerous - typical tory stupidity.
There is no good or workable definition of "terrorist material" - how and who draws that line? What happens with reporters and researchers who view stuff for all the right reasons? What about when I view Fox News (they are total terrorists) or one of my favourite sources, Al Jazeera? What if I sign up for an anti-Brexit site? I'm Scottish - does viewing Independence sites which advocate the break up of the UK constitute terrorism (yet)? Trump, the tangerine shitgibbon, is a global terrorist...is viewing his stuff terrorism (it should be)?
Not that it matters much any more...with Brexit, the lunatic unelected moron in #10 (yes...you, Theresa May) will destroy the UK, and cause it's break up and along the way, a return to the Ireland border "troubles", which is domestic terrorism in all but name.