said by Jabbu:
If you buy your own wifi cable modem, twc will not charge you to use the wifi.
Thanks. I knew I wouldn't have to pay the cable modem rental fee if I bought my own cable modem but I thought they either might know from the MAC address or they would ask me the model number of the cable modem and then once they found out it was WiFi capable they would add on the WiFi service fee. It's good to know that they won't. I tried chatting with TWC customer service but the customer service representative gave me 2 different answers so I came here to ask the real experts.