Ok some real data about fake reviews, check out: "Don't Tap The White Tile" ratings section in App Annie: http://www.appannie.com/apps/ios/app/848160327/ratings/
Now look at the USA rating compared to say the UK ratings. These are two fairly similar countries in terms of app store games, often their charts are pretty similar, so you should expect them to have pretty close number of ratings when normalized for population.
So UK population is 63 million, and USA population is 313 million, so you would expect the USA to have about 5 times the ratings as the UK. The UK has 28 ratings, so the USA should have 140 ratings. But as you can see the USA actually has 8266 ratings, I don't think this kind of difference can be put down anything other than fake ratings.