What is the FDA's responsibility in CAFOs?

Dear Food and Drug Administration,
I am writing to find out what the FDA's responsibility is in allowing Confined Animal Feeding Operations to continue to brutally abuse, neglect, and kill cows, pigs, chickens, and other animals used for food.
Here are my questions:
What is the FDA's position regarding the fact that citizens and journalists are not allowed to visit inside the facilities where these animals are raised and slaughtered?
CAFOs provide the major source of the United States meat supply, so what explanation does the FDA have for allowing what goes on inside the facilities to remain hidden from public scrutiny?
Does the FDA's acceptance of CAFOs mean that the FDA considers animal abuse, neglect, disease, confinement, pain, suffering, and slaughter without access to sunlight and green grass healthy and safe for the American public?
If the FDA does not accept responsibility for the regulation and sweeping reform of CAFOs, what governmental or private organization does the FDA officially defer to on the matter of their reform?
I honestly submit these questions in anticipation of honest answers. I don't understand how the FDA allows CAFOs, based on the dangers they present to public safety, environmental sustainability, consumer protection, and animal welfare. I am also submitting this letter to many organizations as an outcry towards legislation that extends animal cruelty legislation to animals used for food. I am extremely concerned about this issue and urge the FDA to consider the impact of CAFOs on food safety.
Sincerely,
Jadene F

(also sent to the following organizations from http://en.wikipedia.org/wiki/List_of_animal_rights_groups#Animal_rights_organizations:
info@upc-online.org,
info@farmusa.org,
info@farmsanctuary.org,
info@veganoutreach.org,
lobby@aspca.org,
sapl@saplonline.org,
alive@alive-net.net,
info@certifiedhumane.org,
info@animalaid.org.uk,
sharonn@animalequality.net,
Campaigns@peta.org,
animal liberation front ,
aish_hitman@rediffmail.com,
afr00001@students.stir.ac,
asmodeous383@yahoo.com,
info@anonymous.org.il,
chenrezig@shaw.ca,
Kr1st1n4_V@hotmail.com,
info@cala-online.org,
idainfo@idausa.org,
info@massanimalrights.org,
nrdcinfo@nrdc.org,
wwuwarn@gmail.com)