New theory from Cracked.
http://www.cracked.com/blog/you-really-have-no-idea-who-villain-frozen-is/
Basically....the trolls were using Anna as a sleeper agent in their "Cold War" against Elsa.
http://www.cracked.com/blog/you-really-have-no-idea-who-villain-frozen-is/
Basically....the trolls were using Anna as a sleeper agent in their "Cold War" against Elsa.