Instagram Can Sell Your Photos Without Paying YouEDIT 19/12/12: Instagram has responded.Instagram Can Sell Your Photos Without Paying You by RobynRose
Though the language they use seems to want to overly passify rather than address issues. "Your photos are your photos and we respect that." is a nice sentiment but does not necessarily exclude "we have the right to license and use your stuff even though you own the content" By signing up to instagram you are giving them permission to do this even though you do technically own the content you are submitting.
I'm not going to flail my arms about doom, but I will say, artists be aware. Not just about this, but about any contracts you sign. There is some real sketchy language in the fine print here that needs to be clarified or changed as of right now. More than just an "everything's fine, don't worry" letter. Company lawyers have a tendency to try to take the largest chunk of whatever they can, and only back off when their actions are made public and they ar