The majority of easily accessible CF informational web sites do not adhere to guidelines published by the AMA. Patients and families who use the Internet as a CF information resource should examine the web sites carefully and be familiar with the guidelines established by the AMA. Personal information is not protected, and few sites provide explicit privacy guarantees. Finally, CF care teams should inquire about Internet use by patients and families and be prepared to discuss findings from the Internet to heighten patient safety and awareness.