Does Streaming via NetFlix, Amazon, count towards bandwidth usage?

A while back, Comast introduced monthly limits on free Internet usage, started at 1TB and I think it's now 1.2TB.  This was obviously a move to dissuade people from using other TV/Movie streaming services and only using Comcast for their Internet connection as you'd probably exceed your limit if you watched TV and Movies solely from a 3rd party device/service.

My question is, when you use the built-in streaming apps on the X1, as opposed to a different device connected to your Xfinity WiFi, does that streaming count against your bandwidth limit?

If not, I can see even more reason for people to demand from Comcast that they hurry up on adding the Disney+ app to the X1.