According to the Putinista wing, this stories are lies invented to harm the great man and president for life, Putin.
These Russian pilots need to put the voltage bottle down and check their p’s and q’s .....
Well, that is what you get from a reporter; simplistic statements. Commercial radar (and military) uses transponder return signals to identify contacts. The radar doesn't require it to detect an aircraft. However, ATC generally turns down the actual radar returns on their screens, because just looking at the transponder returns is easier, and ATC is focused on traffic management, not detection.
If the Russians keep this crap up, the Baltic ATCs will have to start looking for raw returns.
Russians are no match for us Swedes. They come in large numbers but lack belief in their cause. Tiny Finland has defeated them in war.