Not 1000 protesters. 1000 DETAINED protesters. And during the same day the protests happened all over the country. I may have not been entirely clear in my comment, but you could've at least checked the Wikipedia.

Since the start of the war until 6 March [2022] nearly 13,000 have been detained.

And it's nearly impossible to calculate how many actially participated and escaped before getting detained. And that was before the mobilization, that was when only the professional military was involved. After the mobilization the protests reignited.

And what exactly do you mean by "Russians aren't passively resisting"?