As you know, there is a russian speaking minority of 35% in Latvia from soviet times. Russia has been pushing for LV government to grant citizenship to these people, despite the fact, that they do not speak latvian, nor actually care too much about getting it. State language is Latvian.
In the 90's, there first used to be both Latvian and Russian schools - as in,
state-financed schools, that teach in a non-state language. This was changed, so that they would teach at least partially in Latvian. This caused an outrage, from both the local minority and Russia. Soon, we were labeled fascist, Kremlin controlled media was attacking us non-stop and there were protests against this, by the minority. This is also when they first started attacking us financially, by randomly banning various goods, that were being exported to Russia (i guess sprats too?). Anyways, this went through regardless. Still, the information war did not stop there and continued unabated, to the point where Latvia was, according to some poll done in Russia, its' enemy #1, surpassing even USA
Also, there have been numerous disputes over the fact, that Russia refuses to accept the occupation of Latvia during WW2, as well as the repressions done by SU against Latvians. It's not just a matter of history, as this also caused great problems with signing a border pact with Russia, where they didn't shy away from using our Russian-speaking population against us in various ways. Also, obviously a matter of importance for the families of the repressed or the surviving victims.
Recently, however, there have been concerns about Kremlin financing various political and ideological elements in Latvia, in an effort to destabilize the country. The whole deal with the referendum about making Russian a state language, for example, which was really started by an agitator, that was expelled from Russia. A mainly Russian party is also suspected to receive financing from the Kremlin. During the economic recession, there was a protest, that later turned into a brief riot, with mostly russian-speaking people looting shops (liquor stores, lol) and throwing bricks at government buildings, whilst attempting to escalate the situation further. Most of these were detained later, but some of these, that actually began the riot, are suspected to have not been locals. One of these, a picture of who later became a minor internet meme here, bears an uncanny resemblance to one of the pro-russian protesters, that was taken a photo of... in Crimea ;)
Various rhetoric by Kremlin politicians, about how the Baltics should just get occupied again and fucked over and how Latvians are dogs and whatnot... That's just normal every day business here.
Poll