Facebook echo 

An accidental double-sending of a message on Facebook chat due to a chat error. Happens way too often.

Jon: "Hi!"
Anna: "Hey there!"

"Hey there!"
Anna: "Ugh. Sorry. Facebook echo."
Jon: "Facebook lives in a cave."

Facebook echo by Tomi V. October 21, 2010

facebook echo 

The repeating of facebook status updates and wall posts

"Man if I see roger put carpe diem up as his facebook status I might vomit."
"Total facebook echo"

facebook echo by appa momo January 5, 2010