Jez123 - 3:09 pm on May 21, 2012 (gmt 0)
I think the older the site is, the greater probability that it has unnatural links, assuming it has had good visibility the entire time. Scrapers looking to link to high-ranking sites to boost their own authority will link to you with money phrases. People will also link using the title of your site. Now, if a site is old but was not ranking well for the past few years (poor visibility), there is a smaller chance of scraping, and I've seen some old websites suddenly start ranking because they still have a "natural" link profile, where "natural" is defined by someone at Google. Google needs to study the issue of link scraping in competitive markets as a function of age and visibility and they will see that it is a phenomenon beyond the webmaster's control. If you've over-optimized on-site elements (over linking to commercial pages using commercial terms), that can be reduced/controlled.
I think that what you have described is exactly my problem. Surely I am not going to have to start again with a new site am I? This is just so ridiculous.