Today we are so habituated to online platforms that it’s common to refer to trying to influence “the algorithm.” From what appears in your Twitter or Instagram feeds to what Google proposes in the search bar as you type, to the ads you’re served at every turn, hidden algorithmic processes serve you content and learn from your selections to “train” the algorithm to better meet your needs next time.

But while these unseeable processes shape our online experience, labor is exploited behind the scenes. For an enormous amount of algorithm development, especially in today’s fast-moving AI industry, much of the training is done by “microworkers” — men and women, often in the developing world, who are training these systems manually.

For literal pennies, they take on tasks that may last for minutes or less, like flagging violent social media posts or ranking the relevance of search results. The workers performing these “human intelligence tasks,” or HITs, are as essential for the gigantic platform companies as they are utterly exploited and abjectly disorganized. Phil Jones’s book Work Without the Worker: Labour in the Age of Platform Capitalism allows the reader to see these invisible hands and the challenging frontier of worker organizing they represent.