For the first time ever, I've managed to stump the masses. Does that mean it was too difficult or a tip-toe beyond the line of juuuuuust right. Although, many many many guesses were close, practically encircling the actual city, which was Donets'k, Ukraine; a city of about 1 million people.
Extra bonus points, but no beer, to McCready for answering "Long Island?" to the clue, "what is full of Russians but not in Russia." Apparently, this clue was a bit misleading for some. The source was census data suggesting that the majority of Donets'kians? Donests'kites? were Russian rather than Ukrainian.