Yes they cheated. One of the judges, Yuri Balkov from the Ukraine, is a known cheater and actually served a one-year suspension after the 1998 Nagano Olympics. It wouldn't surprise me one bit if Putin is breathing down the judges necks and/or paying them off to juice the Russian skaters' scores.
The judges were the fair for the other players as the Korean judge and the American judge were not picked. Also the judge did not give the adding point that was supposed to be given to the other players like Yuna Kim. Yuna Kim, the champion of the Vancouver Olympics did not do anything wrong or did not even fall. However, the Russian gold medalist had missed some actions in the performance. And, many of the news of other countries including Germany and America had been shocked since the judges had give much more points to the Russian player. So, it shows the unfairness that the judges had performed, and there is no reason for the judges to be unfair like that except for being payed off. I think that the judgement in the Olympics should improve more. Also, sports game is a game based on fairness and sportsmanship, but this Olympic is not following this. EVERY SPORTS GAME SHOULD BE FAIR!!!
Russia is known for its excellent figure skaters, and if not the best. Best example in Plushenko who sadly had to leave due to injuries. Beside that, just because Russia "stunned" the world with getting a gold does not mean they cheated.
If you want to look at a game that was not fair and biased look at the men's hockey game between Russia and U.S. The American ref and goal watchers deliberately did not move the goal net back to place so that when Russia scored that the Americans could complain that "well, the net was ONE CENTIMETER off so the goal does not count." Sounds pretty biased and unfair if you ask me.
Sotnikova deserved the gold for what she worked for, so everyone that says she cheated is over speculating the matter.
Russia has a great olympics team and there is no denying that. This being said, I don't see any reason why they would have to cheat or anything. Especially since they have home field advantage per say. It's obvious to me many people are just bashing Russia for the simple fact of their political stances.