Yuri Victor

Netflix is alerting its viewers whenever its picture quality slows down through no fault of its own.

Late on Tuesday, Vox Media designer Yuri Victor posted to Twitter a photo of a Netflix screen with a message about a buffering interruption to a video stream. The message wasted no words about where the blame lay: "The Verizon network is crowded right now." Netflix went on to say that it was "adjusting video for smoother playback."

Not long after that was image was published to Twitter, Netflix spokesman Jonathan Friedland tweeted that the feature is being implemented across the network to "keep members informed." Images showing a similar message on networks other than Verizon have not been published so far.

The timing of the shot over Verizon's bow is nothing if not interesting. In April, Verizon and Netflix signed an that the streaming provider hoped would improve video quality. It's believed that the deal, like an earlier one Netflix signed with cable provider Comcast, gives Verizon direct access to Netflix's content delivery network to deliver better quality video.

Despite signing the deals to deliver better quality, Netflix has panned the very fact that it needs to establish such agreements. The company argues that television service providers are unfairly ratcheting back Netflix traffic and should allow for full access no matter what. The company has published a transparency report it updates periodically to show the speeds its subscribers are getting on different networks. Verizon Fios, the service Victor was on, is ranked eighth in Netflix's evaluation with an average speed of 1.99Mbps. The top provider, Google Fiber, delivers Netflix at an average speed of 3.6Mbps.

The issue at play between providers and Netflix is how the heavy data transmission between Netflix's services and customers should be handled. At the center of that issue is the concept of Net neutrality and whether traffic should continue to flow freely through networks or be metered. Netflix, of course, wants to see the free flow of traffic to keep its costs down. Most television service providers would like to have the option of charging companies that use vast swaths of its bandwidth. Chief among those companies is Netflix, which gobbles about one-third of all US traffic during peak Web traffic hours.

The debate over Net neutrality has no clear end in sight. But it is clear from Netflix's latest move that the company is going to try to hold cable providers accountable to customers. So far, Verizon hasn't said publicly how it feels about that move.

CNET has contacted both Verizon and Netflix. We will update this story when we have more information.