In early 2011 Facebook started to send all iframe application requests as POST. Because of this most REST based applications broke. Lets say you have object called
User. To get list of users in RESTful application you would issue the following request:
New user is created with POST request:
I’m sure you can spot the problem here. You try to retrieve list of users. That does not work. Instead you end up creating new object because your request was converted to POST.