Forgot to post this, found it on the MSU Center for Biofilm Engineering...
"What is the industrial significance of biofilm?
Microbial biofilms on surfaces cost the nation billions of dollars yearly in equipment damage, product contamination, energy losses and medical infections. Conventional methods of killing bacteria (such as Antibiotics , and disinfection) are often ineffective with biofilm bacteria. The huge doses of antimicrobials required to rid systems of biofilm bacteria are environmentally undesirable (and perhaps not allowed by environmental regulations) and medically impractical (since what it would take to kill the biofilm bacteria would also kill the patient!). So new strategies based on a better understanding of how bacteria attach, grow and detach are urgently needed by many industries."
So, could this be why we can't kill these things??