By contrast, with a more standard sneakernet, you'd need to know everyone you're in direct contact with -- but that number is typically kept fairly low for social reasons anyway. Data would be distributed more widely by passing through several intermediaries: Bob copies all of Alice's data, then Carol copies Bob's, and now Carol has Alice's data without necessarily having met. This is how people used to pirate software before network access was so common, and it actually worked pretty well.

Want to know who to blame for all the old games asking you to "look up this word in the instruction manual"? It's people doing this.