I've never came close to 250Gb,that includes d/loads,netflix,amazon,and now WWE network.Unless you constantly go over 250Gb I don't think they will pay much attention.
Yeah, I'm not saying to go torrent all day and try to download 1TB+ every month. Don't start running a web server on a residential account or racking up big downloads just because you can. I'm sure they do warn or disconnect the worst offenders.
I'm just saying use the internet how you want to. Maybe some ISPs are stricter than others but I think people tend to overreact to data caps. I feel comfortable using the services I want to without constantly worrying about a data cap. If I want to marathon House of Cards on Netflix or watch baseball on MLB.tv all day I do it. If I want to play a 50GB game I bought I download it. If Charter isn't bothering me about using too much data they won't be going after most average consumers.