Amazon's Kindle Fire has general parental control tools, but Instant Video has so far come up short compared to competitors like Netflix. Now, Amazon has quietly added a set of parental controls for the streaming service. As Tech of the Hub noticed, going to the "Settings & Devices" section of Instant Video will bring up a ratings page and a list of devices. Each device can be set with the slider, after which restricted videos on it will appear with a lock. To make changes, viewers input the same code used to make purchases, but it looks like it's only possible to override controls from a browser, and controls on the Xbox 360 apparently aren't supported. Amazon hasn't announced the change, and we're not sure exactly when it was implemented. The Kindle Fire's controls, which were added in May, only disabled access to specific content libraries on the device itself.