Sonny is right. Here's what happened:

Citizens of the former USSR had to carry internal passports that identified their republic of national origin, i.e., Ukraine, Kazakhstan, Beloruss, etc. But Jews had to carry passports stamped "Jew," no matter where they were born. That was a reflection of Stalin's bigotry--he called Jews "rootless cosmopolitans" (It also had an unintended consequence: it was dangerous to be a Jew in the USSR, but Stalin's bigotry forced Jews to remember who they were--he inadvertently kept Judaism alive in the USSR.)

The Soviet economy began to crumble in the Brezhnev era. and a large-scale conterfeiting industry sprang up to produce "official" permits for businesses, etc. In 1974, the US passed the Jackson-Vanik Act, which gave the USSR favored nation trading status in return for letting Jewish citizens leave for Israel or America. Overnight, counterfeit internal passports stamped "Jew" became worth their weight in gold because they let the holder--often non-Jewish gangsters who ran the counterfeiting rackets--leave the USSR for richer territories.

Today, Jews are probably a minority among the so-called "Russian Jewish Mafia" in Brooklyn's Brighton Beach. Funny example: some years ago the cops arrested the biggest "Russian Jewish" gangster in Brooklyn. His name was Marat Balagula. The laugh: "Marat" is not a Jewish surname, and "Balagula" is Yiddish slang for "bad guy" or "gangster." Evidently Marat forged his own phony internal passport and put "Balagula" on it to identify his profession.