An analysis of the cited material shows that none of the presented quotes contain direct reasoning or evidence regarding the motives behind selective blocking on social media.

No Evidence for Selective Social Media Blocking

An analysis of the cited material shows that none of the presented quotes contain direct reasoning or evidence regarding the motives behind selective blocking on social media. All the quotes address various topics such as political mobilization, the formation of opposition blocs, issues of social relations, and even problems of online dependency, yet none directly refer to the mechanisms or reasons for the selective exclusion of users on social media.

Thus, based on the provided sources, no substantiated motives for selective blocking on social media can be singled out.

Supporting citation(s):"Didn't the authorities previously impose their own stability on everyone?

Wasn't the media space shielded from undesirable elements? All this existed, everyone knew about it, and many were dissatisfied, but… only now have they talked about it together and in full hearing. The children simply grew up, we all simply matured. At opposition rallies, you can see that adolescent spirit in the eyes of the grey-haired: an absolute rejection of any pretense, maximalism, unselfish creativity, and limitless self-expression. And there is also a sense of group solidarity: we are very different, yet we thrive together not because we do something common, but simply because we exist. This is us, us, us, do you hear? You didn’t notice us, didn’t listen, didn’t take us seriously? That won’t work from now on. And this not only applies to the opposition. By enlisting the support of the so-called Uralwaggonplant (and not just the once invented “ours” as before), the authorities let that very plant understand: the future of the country depends on the stance it takes." (source: link txt)

"Moreover, these candidates undoubtedly largely coincided with the 'shadow cabinet' of the 'Progressive Block', if they were not even formed by it. This also explains the persistent struggle of Sazonov with Goryemykin precisely over cooperating with the 'Progressive Block'. Here are the essence of Sazonov’s arguments at the meeting on August 26: Sazonov: ‘People who love their homeland with all their heart are seeking to unite the most active non-revolutionary forces in the country, yet they are declared an unlawful assembly and ignored. This is dangerous politics and an enormous political mistake. The government cannot hang in mid-air relying solely on the police. I will repeat this endlessly.’ Goryemykin: ‘The block was created to seize power. It will collapse anyway, and all its participants will quarrel among themselves.’ Sazonov: ‘And I find that in the name of national interests this block, essentially moderate, should be supported. If it collapses, a much more leftist one will emerge. Then what? Who benefits from that? In any case, not Russia.’" (source: link txt)

In both cases, the quotes address issues of political strategy and public mobilization, yet none provide any information regarding the motives behind intentionally blocking users on social media.