The Director General of Security or the chief officer of an interception agency must not give a technical assistance notice to a designated communications provider unless the Director General of Security or the chief officer, as the case requires, is satisfied that:
(a) the requirements imposed by the notice are reasonable and
proportionate; and
(b) compliance with the notice is:
(i) practicable; and
(ii) technically feasible
So I don't believe intercepting en masse the communications of all the visitors to a web site purely based on its name would be seen as "reasonable and proportionate".