One of the catalysts were probably 1999 bombings of apartment buildings[1] that were very suspicious (including one where FSB were actually caught planting hexogen by a local militia) and led to dramatic rise of Putin.
Along with crackdown on media it created a narrative where you have a strata that must have their rights removed and be hated by society. First it were "terrorists" and then to a different degree "opposition", "journalists", "LGBT", foreigners and Ukrainians.
Along with crackdown on media it created a narrative where you have a strata that must have their rights removed and be hated by society. First it were "terrorists" and then to a different degree "opposition", "journalists", "LGBT", foreigners and Ukrainians.
[1] https://en.wikipedia.org/wiki/Russian_apartment_bombings