tedster - 8:19 am on Jul 24, 2009 (gmt 0)

I'd say yes - evidence of mass link building efforts can sometimes hurt rankings rather than help. You might say that you can google-bowl your own rankings.

This Google practice sometimes opens the door to your competitors being able to hurt your rankings, under some situations. The competitive situation isn't that simplistic, and Google does work to limit the possibility - but they also acknowledge it by saying that "There's ALMOST nothing a competitor can do to harm your ranking..."

See [google.com...]