We recommend you to check the site above since it contains information about plagiarism. The site shows information obtained from a study in which they identified which were the most plagiarized sources by students when doing a work. The study showed important results since the sites, were students get their information from, are mostly pages that anyone can edit, like wikipedia, Yahoo Answers, slide share, among others. It is very likely that the information found in these sites is already plagiarized. The amount of plagiarism done by students is impressive. Schools need to take more severe measures regarding plagiarism, as well as teach how to prevent it and apply harsh measures to those who do not give credit to the author.
Campus technology. (2011). Wikipedia Tops List of Plagiarized Sources. Available at https://campustechnology.com/articles/2011/11/03/wikipedia-tops-list-of-plagiarized-sources.aspx