Let me give an example -- I wrote some code to scrape real estate listings, populate my own DB, and a front-end to rank properties and track changes. It polls the listings and lets me know when things change.

At this point it's just code I wrote for my own use. I can't see how that's copyright infringement, but even if it were, it's just me organizing data on my own machine. There's no distribution, there's no commercial element. I could achieve a similar result pinning printouts to a bulletin board.

Now, let's say tomorrow I open up a Github repo and post the code under an MIT license... Someone wants to download and run it, they can. The program doesn't serve any content to anyone else, there's no P2P going on here. There's no sharing, or inducement to share.