She challenged Twitter... and Twitter won. Kelsey Hall is a student at the University of Alabama and is probably regretting her decision to post this photo of herself wearing a Christmas tree costume. She posted to her 300 twitter followers that if she got 1,000 retweets, she would wear the costume to class for the rest of the semester. She posted the photo on Dec. 2nd, and well... its pretty clear she got over the 1,000 retweets she was looking for.