> Any highly corrupt society is bound together by a series of interlocking reciprocities: the local policeman who shakes down a passing civilian must in turn pay tribute to his police supervisor, who must pay his supervisor, and so forth; favors or spoils may be distributed in the other direction.
My guess is the cops justify their work like in Stanford prison experiment, and they accept without further thinking what Putin says that the protesters are "foreign agents".
[0] https://nationalpost.com/news/world/cost-of-corruption-in-ru... [1] https://www.newyorker.com/magazine/2015/01/19/corruption-rev...