Webcopy and duplicated content

Google and the other search engines allow a small % of copied / similar text in relation to the bulk of the text before it gets flagged up as copied. Recently was given a page with 1200 words (in a standard questionnaire format) the question titles do not result in the page getting flagged up, but when the text body has multiple exact streams of words copied from another website it will gets flagged up.
In some circumstances the search engine will not index a page when its deemed to be copied text, this does harm to the website search engine rankings, obviously. I would go on about readability algorithms and metrics but think you will start to hate me.