"There has been a gang of Islamists convicted of plotting mass murder every year since then, and several some years."
Can you provide links to this - the only claim I can find is on the fascist "Stormfront" website?
yes I can, and I never look at such sites.
Nor should you.
They use hits as evidence of support.

Asked if MI5 was in the dock, Sir Malcolm (Rifkind, former defence sec.) told BBC Radio 4's Today programme: "No, I don't think they're in the dock. I think that would be very unfair.

"Do remember one fundamental point: the fact we have not had anyone killed until these tragic events in Woolwich since the 7/7 bombings in 2005 is not because there hasn't been terrorist plots.

"Every year since 2005 there has been at least one, sometimes two or even more, terrorist plots which were disrupted and prevented from killing British citizens, partly because of the work of MI5 - in some cases very largely because of the work of MI5 - and other intelligence agencies."