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Satellites can only look down from above, so unless you have skylights (windows in the roof) they cannot look in your windows.
And no satellite can watch one place on the ground continuously even for a short time. The satellite can take one snapshot as it flies over, and it can fly over any one place on the ground at most twice per day; but usually less often than that. Except for the poles. Spy satellites in polar orbits fly over the north pole every 90 minutes, and over the south pole every 90 minutes too, basically flying over on pole, then the other one 45 minutes later, then the first one 45 minutes later still.
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The technology to do that exists, but there aren't nearly enough satellites. or people monitoring them, to watch the whole world. Besides, it's far easier for the government to hack the webcam built into your laptop or computer or even phone, and watch you through it without turning on the indicator light. But normally they only do that if your ex is a government agent and is feeling bitter.
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They cannot and likely will never, but what you type on face book or even answers.yahoo, may be held against you in determining your sanity in 2050 or even farther in the future.