1 {scene: A control room, Mars}
1 Martian 1: For our next attempt to invade Earth, we plan to start by removing their leadership.
2 Martian 1: This is the most powerful and popular leader on the planet. {gesturing at a hologram of President Allosaurus} Unfortunately, he's surrounded by security and highly trained combat experts.
3 Martian 1: Any suggestions?
4 Martian 2: Drop an asteroid on him?
4 Martian 3: Oh sure, like that will work.
4 Martian 1: Hmmm...

Notice how the Martians are using a tape drive on their computer console table thingy.

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2018-08-01 Rerun commentary: When I did my Ph.D. studies, we students had a disk quota on the Physics Department mainframe computer. The quota was 10 megabytes - yes, megabytes, not gigabytes - and it was strictly enforced. You could use up to 12 megabytes temporarily, but if you were still over 12 megabytes after 24 hours, your oldest files would be automatically deleted until the total was below 10 megabytes again. And the system wouldn't let you write files that would take your total over 12 megabytes.

When students graduated, all their files were deleted, to recover that valuable disk space. So when I graduated, the Ph.D. thesis that I'd spent three years researching and a year writing was deleted. It was backed up on to a tape drive, because the faculty didn't want to permanently lose the digital copy. At the time, I did not own a computer and I didn't have an email address other than the university one, so there was no easy way for me to keep a copy of the files myself.

A few years later, when I had my own computer, I returned to the university to ask for a copy of the files that comprised my thesis. Unfortunately, the backup tape couldn't be found anywhere! I still have no idea what happened to it.

And so despite having typed out the whole thing into text files and having produced digital versions of all the figures, the only copies now in existence are printed hard copies, plus a PDF scan I made a few years ago so I could have a digital copy. The scan includes OCR text, but for a technical work with lots of equations, tables, and Greek characters, it's not anywhere near as useful as the original typed text would be. (If you're interested, the scans are linked from this page, but it's probably fairly boring to anyone not interested in astrophysics.)

And now it's laughable that something could be lost forever because of a policy designed to reclaim a valuable 10 megabytes of disk space.