Finding large scale duplicate content

There’s often talk of a “duplicate content filter” on Google.

In other words, if Google finds the same material on different sites, it gives preference to only one.

So imagine my surprise when I did a search for the anchor text used in an unauthorised code insert on one of my sites, as reported here:

Follow this search: flash siemens c60 500

Looks like Expansys have been busy - they appear to have duplicated the same content across a large number of domains, often national ones.

In the top 100 results on Google, they occupy 25 positions, including 1 and 2 - all showing almost the same content.

I guess the lesson is that Google is more susceptible to duplicated content than some people are led to believe.