You know how you still don't have Google Fiber in your area, even after offering to relinquish your immortal soul to Google? Well, there's about to be yet another reason to be sad about that. Google is preparing to add Cast support to all existing Google Fiber TV boxes. However, there are some weird restrictions.

The update will start hitting Fiber TV boxes in the coming weeks. After the update is live, Cast-enabled apps will see the box as a receiver for streaming content. You won't even have to switch inputs to use the cast feature. That's neat, but the Fiber TV box won't act like just any old Chromecast. Some apps simply won't stream on the box. Here's the situation, according to Google's support page.

Some cast-enabled apps might not be available to cast entertainment to your Fiber TV. Currently, these include Hulu, WatchESPN, Disney Channel, Disney Junior, Disney XD, WATCH ABC, Spotify, and HBO NOW.

Note that HBO GO, which is included with a subscription to the HBO Optional Package or the Premium Package, is supported...

Notice anything there? Disney owns or is heavily invested in most of those services. Then there's HBO Now (doesn't require cable) that is blocked, but HBO Go (comes with cable subscription) works fine. There could be a technical reason for this patchwork of app support, but I'm betting it's a business thing. If Google wants to offer TV service, it has to play ball with broadcasters.