Large protests erupted in Moscow on July 20, 2019, but different media outlets reported vastly differing crowd sizes.

Protesters in Moscow gathered to demand that opposition candidates be allowed to register in the Moscow municipal elections, to be held in September. The protests were unsanctioned, but riot police did not disperse them immediately. Nonetheless, pro-Kremlin media outlets diminished the size of the crowd in their reporting.

Activists gathered when the authorities barred around 30 candidates from registering on the pretense that they had obtained invalid supporters’ signatures. Multiple Western media outlets, including BBC and Reuters, reported that at least 20,000 protesters gathered on July 20; Kremlin outlet RT, meanwhile, reported that only 12,000 protesters showed up. The Russian video news agency Ruptly, which belongs to the RT news network, published a video on YouTube that showed an overview of the crowd as people started to gather, suggesting that the crowd was on the smaller side.

A Ruptly video reporting on the July 20 protest. The first frames showing the overall size of the crowd were taken as the crowd was only starting to gather. (Source: Ruptly/archive)

Surfaced videos taken during the protests, however, revealed that the crowd was significantly larger and more dense than Ruptly had suggested.

A video taken from the protests showed the density of the crowd on July 20, 2019. (Source: @alexkokcharov/archive)

A prescise crowd size estimate requires two main pieces of information: the crowd density, and clear boundaries of the crowd. This information allows for a precise estimate of the average size of the crowd using open source tools.

The density of the crowd can be estimated by counting the number of people in the crowd standing in one square meter. According to the Google Maps satellite imagery, the area between the two traffic marking lines seen in one of the photos is approximately 1.7 meters wide. At least four people can be clearly seen standing in the area. The same distance measured vertically suggested that at least four people were standing along the vertical axis, making the average density of the crowd less than two people per square meter.