According to Darnton, hacks constitute a group of struggling writers (a "literary proletariat") who cobbled together a living by engaging in a range of practices: underground journalism, pamphlet-writing, education, spying on other intellectuals for the police, etc.
This alienation bred an active hatred of the hierarchies of the Old Regime, and fueled the radicalism of the French Revolution (since many hacks wound up in power after 1789).
Examples of French hacks include Pidansat de Mairobert, Simon-Nicholas Henri Linguet, Jacques Pierre Brissot, Jean-Paul Marat, and Nicolas-Joseph-Florent Gilbert.
Hacks typically wrote radical, salacious, or subversive literature, such as plays, novels, and pamphlets about controversial subjects.
Darnton states that libelles tended to communicate a revolutionary point of view that showed social rot was consuming French society, eating its way downward from the top.
It acted as a grapevine circuit in which publishing houses would print and manufacture the literature and then networks of workers would smuggle it into France.
Within Darnton’s book he presents historical anecdotes of individuals who were involved in the publishing, manufacturing, and selling of illegal literature.
In order to properly distribute and sell the books it was almost always necessary to have a police connection to make sure the goods got smuggled into France, and to the appropriate party.
Darnton states that there was an emphasis on scandal where private decadence became a public issue, and by slandering eminent individuals, they criticized the whole regime.
This literature was illegal and the police had the responsibility of censoring and banning these works that sought to discredit the regime that ruled over the French kingdom.
Political material such as pamphlets and other pieces of underground journalism through this medium it was possible for citizens to be slightly informed on current events since there was no newspaper that circulated within France during the Old Regime.