Beware of your cable company right now. They are usually also your Internet provider. Recently, many Internet companies have started charging usage fees. This means that the unlimited package you signed up for, now has limits. To make matters worse, if you pay an exorbitant fee to upgrade back to unlimited, you will just pay more. But, do it on time, or you will incur usage charges at far more than the new rate.
In my case, Cox Communications is my provider and they charged me $99/month for unlimited premium Internet until January 2018. Today, I got a bill for $200+. I used 1.7TB of my 1.0TB allowed. Now, I had already upgraded to the new $149/month price to retain my unlimited usage, but "they billing cycles on the upgrade and your regular billing are different" which they did in fact adjust. I guarantee class action lawyers are foaming at the bit right now.
What causes high use on the Internet? Streaming media, like games, movies or other content using the Internet rather than the TV bandwidth. Often, you can't even tell, but if it's an AppleTV, a PlayStation, Roku or other similar device, or an "app" on your TV, it's streaming. Also, music services like Apple Music, Spotify and Soundcloud are streamers. And DO NOT FORGET your security cameras are uploading video streaming to the cloud all day, all night! These are monster bandwidth suckers!
So, be careful and make sure you have your plan set proper. Don't get caught with high usage charges.