  Disinformation continues to attract attention due to its increasing threat to
society. Nevertheless, a disinformation-based attack on critical infrastructure
has never been studied to date. Here, we consider traffic networks and focus on
fake information that manipulates drivers' decisions to create congestion. We
study the optimization problem faced by the adversary when choosing which
streets to target to maximize disruption. We prove that finding an optimal
solution is computationally intractable, implying that the adversary has no
choice but to settle for suboptimal heuristics. We analyze one such heuristic,
and compare the cases when targets are spread across the city of Chicago vs.
concentrated in its business district. Surprisingly, the latter results in more
far-reaching disruption, with its impact felt as far as 2 kilometers from the
closest target. Our findings demonstrate that vulnerabilities in critical
infrastructure may arise not only from hardware and software, but also from
behavioral manipulation.
