The existing expectation of privacy assumes the capabilities of regular human beings. Humans cannot reasonably observe thousands of different locations simultaneously, 24/7, and remember of millions of faces. Machines can.
An analogous example: There's no speed limit for walking/running because human beings cannot run fast enough for it to be a problem, but we had to come up with speed limits for cars because they could do much more damage due to how fast they could go.
An analogous example: There's no speed limit for walking/running because human beings cannot run fast enough for it to be a problem, but we had to come up with speed limits for cars because they could do much more damage due to how fast they could go.