These images are created by "stitching" together many pictures (think thousands) with computer software. The time to process all that data would make it impractical to use this technique on "everyday" surveillance, but would be worth the effort for historical events, such as a presidential inauguration.

That's not to say TPTB aren't working toward the goal of "infinite" zooming of pictures of the populace, however...

Big Bro can read all my posts, all my emails, all my comments, and etc.
I don't post anything on the net that's private.  I haven't done this since I entered cyberspace in 1995.  For Big Brother's information, my first computer was called doggydo, my password was da18ala, and my company was Millenium Industries.  When the internet began accessing bank accounts I took my money and ran.  I quit using Ebay with the dawn of Paypal.  I remember the good ol' days of the internet, when websites were run by intelligent people and searches on Yahoo were truly informative.  Back in the day you could quickly find the most trivial information on the web, from which oak tree had the biggest acorns to who won last years Iditarod. 
When I worked at Angelus Press we had a hard time keeping track of 1500 hundred subscribers.  I'm sure the NSA can't even tell a Siberian Husky from a Timber Wolf, or a Siamese cat from a white lion.  Big Brother might be watching, but he hasn't graduated from kindergarten, as contemporary internet fare proves.

Our Lady of Fatima Pray for Us, you are our only hope.

C'mon!  Someone spent that much time stitching??  For what purpose?

Not someone, something. It's done with computer software and little human interaction. Camera sensors have only so much physical "real estate", so in essence, this software creates an image only possible with a camera sensor a thousand times bigger than what is currently available. Google "gigapixel image" for examples of this technique used in art, science, etc.
https://en.wikipedia.org/wiki/Gigapixel_image

EDIT: They have one for Trump's inauguration, too: http://www.cnn.com/interactive/2017/01/politics/trump-inauguration-gigapixel/

C'mon!  Someone spent that much time stitching??  For what purpose?

when Pius X said that he didn't know Francis