Quite a few links, including the "Contact" page for every topic, are just showing an error message "Data.gov encountered an unexpected error. We apologize for this inconvenience and assure you that work is underway to correct this problem. Please check back in 15 minutes and thank you for using Data.gov." (which appears to be the same text they show as their generic 404 message.) For example https://www.data.gov/contact and https://www.data.gov/climate/faq