How much dup content triggers a drop from SERPs?

Can scraper sites really affect your ranking?

[girish]

The following snippet appears on today's WebmasterWorld home page:

Oct. 27 Interview with Bill Gates about Google Posted in Google Search News by NoLimits... (excerpted from a news item...) "On his first-ever trip to Israel, Gates praised Prime Minister Ariel Sharon and Israel's contributions to the global high-tech market..."

The snippet is linked to [webmasterworld.com...]

If I search Google using the phrase "Gates praised Prime Minister Ariel Sharon" the original new source page ranks #1 and the WebmasterWorld thread page (with 29 messages, so a lot of other original non-duplicate content is on this page) ranked behind several news sites at #9.

Would this demonstrate that all things being equal, that if a scraper copies 3-4 lines of content from your site, that in itself should not reduce your ranking for those phrases (i.e., no dup content filter applies) unless the scraper was considered an authority site more mportant than yours?

edit-- checked 10 minutes later - now WebmasterWorld is ranked #12