I've gotten more than a little concerned lately over a trend I see in the SEO world. I've noticed through following the backlink acquisition of several client sites that the better a site ranks (for a wide variety of phrases), the more spam/scraper sites will re-publish your text or site description from the SERPs and link to you. A thread on the subject of bad neighborhoods linking to sites is active at HighRankings today. That thread notes dangers on both sides of the issue:

#1 - Your site could become targeted by so many scrapers and spammy sites that they overwhelm your legitimate links and make it appear that your site is primarily in "bad neighborhoods".

#2 - On the flip side, sites' link popularity will be boosted so highly from all these links (even with very low value) that they'll remain perpetually in the top rankings, despite becoming irrellevant over time.

The thorniness comes from the massive difficulty in tracking, tagging and removing the value (positive or negative) from millions of URLs. The search engines have a daunting task ahead to stay a step ahead of the more clever scrape & re-publish software and errors on either side could cause big problems in the SERPs.

For an example, note this linkdomain search, showing 15,000+ links (you can actually browse to page 99 and see that there really are that many). Since, in the last 6 months, the site (a client of ours) has only gotten referral traffic from about 2,000 URLs, I can assume that at least 7,500 (half), if not many more, are simply scrapers. That's a very, very high percentage of links that are "bad neighborhoods". I have to wonder how effectively this can be combatted...

If you've got experience with scrapers or "neighborhoods" damaging sites, please let us know below. The more evidence, the better.