Read this article about prominent sites banned by Google from AdSense [inc.com] for content violations that were subsequently reinstated. The article cites several instances where Google made curious mistakes. Then it discusses how non-native speaking English speakers in India are performing rating and review activities for companies like Google.

...raises the questions of whether the people who perform the review are necessary have the training, cultural references, or even English skills to perform the work. One reviewer that the authors met in India had to ask her teenage sons whether some word was "bad" in English. She allegedly does temp work for such companies as Microsoft, Facebook, Twitter, and Google to "train the algorithms that will curate online content."

[edited by: martinibuster at 3:37 pm (utc) on Jan 15, 2017]