Do people think the people protesting like this don't know that this is damaging? They presumably feel that the issue at hand is more important than that damage. Every protest every has been met with "but this protest is being done the wrong way, don't inconvenience me", but that's the point: protest has to disrupt things to make people take notice and make changes. Would I do this? No. I don't think it's effective o…
As a Russian, you already notice this and you already have many things in your everyday life disrupted. Someone deleting your files as an act of shoving politics where it doesn't belong helps absolutely nothing. If anything, it's not an act of protest, it's an act of vandalism. Causes don't matter here — vandalism is simply never okay.
Neither is invading another country.
Someone didn't delete the files. You deleted them yourself by blindly trusting 3rd party software that you got for free with no guarantees of anything.