A lot of noise was made about Instagram and the changes they made (and then unmade) to their Terms of Service. If you haven't paid attention to the whole situation, here's a brief rundown:
December 17: Instagram announces changes to Terms of Services.
December 18: Instagram co-founder, Kevin Systrom, posts a blog entry saying Instagram is “listening."
December 20: New, updated Terms of Service announced by Instagram. Advertising section reverts back to October 2010 version.
While I'll admit that I was one of those who was looking for ways to not use Instagram in the future, I wasn't about to "rage quit" Instagram. Online services such as Instagram, Facebook, Twitter, have the right to change their TOS and other agreements as they see fit. It's up to Instagram to balance the needs of the business (i.e. make money) with keeping users happy. As much noise was made by many users across the Internet, this likely doesn't hurt Instagram in the long-term.