An Algorithm for a Better Bookshelf

"Their new algorithm adapts to an adversary’s strategy, but on time scales that it picks randomly"

"Even though many real-world data settings are not adversarial, situations without an adversary can still sometimes involve sudden floods of data to targeted spots, she noted."

This is pretty neat. I bet this will find practical applications.

Are "adversaries" broadly used in algorithm design? I've not seen that before. I'm used to edge cases and trying to break things, but an "adversary", especially white box, seems different.