People, especially unskilled workers, can be exploited through a sweatshop. This means that someone else uses the people's knowledge or skills in order to make them do something for them. Socialists (or communists) often talked about the "exploitation of the masses" when they were saying that Capitalism was bad. They meant that a few rich people were using all the working people to do hard work for them but paying them very little. The employers then sold the products for more money and kept the extra as profits so that they themselves could become rich.