Definition of "surveillance"

Lady Anne appeared in a week or two to have greatly recovered her appetite, and she talked much of the benefit derived from her native air, in order to gain which, she constantly drove out in Lord Rotheles's carriages, and appeared to derive comfort from her admiration of his beautiful bays; beyond this Helen could not perceive that her airings were useful, as her cough increased exceedingly, and all the visitants at the castle expressed surprise "that she did not place herself under the surveillance of one or other of the great physicians of the metropolis."

1842, [anonymous collaborator of Letitia Elizabeth Landon], chapter LIV, in Lady Anne Granard; or, Keeping up Appearances. […], volume III, London: Henry Colburn, […], pages 66–67

The threat of terrorism to the British lies in the overreaction to it of British governments. Each one in turn clicks up the ratchet of surveillance, intrusion and security. Each one diminishes liberty.

2012 December 14, Simon Jenkins, “We mustn't overreact to North Korea boys' toys”, in The Guardian Weekly‎, volume 188, number 2, page 23

Cook was making an impassioned plea to end the technology industry’s collection and sale of user data. “This is surveillance,” he continued.

2019 January 31, Ian Bogost, quoting Tim Cook, “Apple’s Empty Grandstanding About Privacy”, in The Atlantic‎