Instagram voluntarily pulled the plug on its Twitter photo integration on Wednesday, upping the stakes in a growing turf war between the rival social networks.

Previously, when Instagram users tweeted about their latest Instagram photos, the image would appear inline with the tweet. At the moment, those inline images are cropped and improperly formatted in mobile apps. Going forward, the images will cease to exist at all in any Twitter product, according to Instagram.

Early chatter speculated that this was the latest act of Twitter revoking access, as it recently did with LinkedIn and several other third-party apps. But Twitter posted a status update pointing the finger straight at Instagram, and Instagram founder Kevin Systrom defended the decision on stage Wednesday at the Le Web conference in Paris.