Good catch!
Yes, we all know how costly click fraud is at PPC engines. I think the estimate of 38% for Google Adwords is accurate, a similar number occurs via overture. And those two engines have the BEST fraud prvention measures in place.
Findwhat is probably closer to 90% fraudulent traffic. Smaller engines like looksmart, epilot, kanoodle and Enhance seem to average 99% fraudulent traffic.
IMO spending money on anyone other then Google or Overture is a Total waste of money.