I would like some examples, you know?
Well, one of the key things about them is that their specialty is their invisibility :) You can actually read about some of their missions but they release limited details because it would compromise them. There were a couple of movies made about some of their missions. But the one that you can see for real ( a small part of it) is the siege of the Iranian Embassy in London, to free the hostages, which was captured by the cameras on live television.
Interview with one of the SAS men who took part in the mission:
youtube.com/watch?v=8eZuGXJt0Hc
Some of the footage filmed:
youtube.com/watch?v=_p4DmuGyehc
They are not allowed to operate at home
Siege of Iranian Embassy, London?? Oh, and of course Northern Ireland which is part of the UK.