Anecdotally, I can say that there is a strong distrust of Russians stemming from the various occupation of Baltic states as recently as 1991. [1]

[1] Source: My wife's estonian grandparents

I wouldn't say this is necessarily true in younger generations. I grew up with kids from Russian families in school & kindergarten and the distrust of Russians instilled in you by your parents quickly fades.

Older generations are a bit more problematic in this regard. I would say there's a general hate towards older Russians that still can't speak Estonian, even from younger generations.

However, I would say Russians are generally disadvantaged in Estonia and that's a big source of issues. In my childhood, younger Russians tended to be poorer and therefore were more involved in various criminal activities. Most of my friends and I were afraid of Russians in our area, as they liked to pick fights and generally mess with you.

The comment above you added a bunch.