>> Extraordinary claims need extraordinary support.
Then just do it yourself regarding the "Eastern Europeans
enslaved by Soviet leaders" one then! As illegally crossing a border will get you detained or fired at in almost any place now and ever, just as politically-motivated oppression is not a Soviet invention (i. e. McCarthyism, for ex.). Regarding the emigration-preventing regulations, that may be a perfectly understandable brain-drain prevention practice stemming from the difference in income equalities between the blocks (a qualified worker would sometimes earn more than the factory's manager to the East of the curtain, a scientist with a well-established career earned enough, too, but less than his colleague on the other side, most probably, and a humble cleaning lady was a complete different story, I'm sure).
Speaking of seeing PR, and the civilized practice: the folks in question are not "a rock band who dared to say no to the dictator from a Cathedral stage (in music!) and were imprisoned", but rather a group of political hooligans, known initially for a group sex orgy in a museum (and an another alike event, which I'll not describe here), who then performed several rush-into-cathedral-and-start-cursing-and-jumping-around-with-a-guitar (sound to be overlayed later) acts, until finally getting whoever saw this pissed off enough for the freaks to be handled to the police (and then, the infamous trial happened).
(coming from your original "See PR" -- you may indeed go and see the pictures).
Regarding renowned Wikipedia researchers in question -- you don't have to be one to highly doubt their claims: with nearly every family in ex-USSR losing members during what is called The Great Patriotic War here (the total losses are officially > 20 M), both the collective consciousness of the nation, the witnesses still alive, and their families share the memories of the losses' severity. Same applies to the 1936-39 repression era (< 2 M executed being the official figure), the ratio of "official figure" / "perceived impact", most importantly, seeming to be close to that in the case of the War. Now, the events costing 60 M in human lives would have roughly x3 the impact of the War, and still there's nothing like that -- which brings to a conclusion of roughly a 60/20 * 20/2 == 30x hoax!
And don't you dare to say that living here, we "don't know the subject enough" :)