The paper argues that censorship is an economic activity in which both censor and target incur costs, and that binary 'blocked/unblocked' models are as unrealistic as an omnipotent global adversary. Technology changes (e.g., moveable type, online publishing, trusted computing) can shift the cost parameters dramatically, making quantitative cost modeling — rather than binary vulnerability analysis — the correct framing for censorship-resistance evaluation.

Discretionary P2P networks avoid the social-choice and incentive-manipulation problems inherent in random distribution, which requires collective agreement on a system-wide resource ratio (rs, bs) and thus creates incentives to subvert voting or reputation mechanisms. By allowing nodes to self-select content, discretionary systems need no election schemes, reputation systems, or electronic cash, enabling simpler and more stable designs.

§7 defense

Under the paper's economic model, the aggregate censorship-resistance defense budget is always at least as large in a discretionary P2P network (nodes serve content they choose) as in a random-distribution network: for every node i, td ≥ ts, so the total cost imposed on the censor satisfies Σtd ≥ Σts. Equality holds only when all nodes share identical preferences (ri = rs); in all other cases discretionary distribution is strictly harder to censor.

§5 defense

In a random-distribution network, nodes whose utility is non-decreasing under censorship will set their defense budget to zero. For example, in a network with rs = 0.5 (equal red/blue), a censor shifting the distribution to rc = 0 (all blue) increases the utility of strongly blue-preferring nodes; they then invest nothing in resistance, reducing aggregate network defense.

§4–§5 defense

Under the paper's quadratic utility function and linear defense probability P(t) = t/T, a node will invest zero resources fighting censorship when the censor's imposed distribution reduces its utility by less than half (i.e., when Ui(rc,bc) ≥ Ui(ri,bi)/2). Nodes whose preferences most diverge from the censor's are the first to resist; mild censorship therefore attracts little aggregate resistance.

§6.2 evaluation