Unfortunately it doesn't look like Charter actually has a way to see how much bandwidth I use per month.
But I definitely use my internet all the time for streaming Netflix, Hulu, Giant Bomb videos, YouTube, downloading games, and so on. Thankfully I haven't been contacted about excessive usage since going on Charter 1.5 years ago.
Comcast implemented a 250GB cap, but then promptly suspended it due to bad press. (Which is strange because apparently only about 1% of their customers exceed that goal.) With Netflix's improved HD streaming, if you have your settings at "high" you are basically eating up 3 to 3.4GB per hour of video. I've lowered mine to medium (.7GB per hour) for TV shows. Movies get bumped to the highest setting.
With Comcast, you can log on at any time to their website and view your usage.