Mathematical modeling of protest campaign dynamics requires a description of the motivation for action and for inaction. When describing the motive for inaction, the safety-in-numbers notion is commonly used, which means that an individual considers it relatively safe to participate in protest events with a high turnout, since the possibility of becoming the target of repression is distributed among a large number of participants. However, the issue lacks empirical corroboration or refutation. This paper addresses the issue. The case of the 2020 protest campaign in Belarus is considered.