Does tmobile charge you for Wi-Fi if you have no data plan?

I recently got an unlocked iphone, and I'm using it with my tmobile account. My question: I have no data plan, but if I turn off 3G and ONLY connect to Wi-Fi, will they still charge me? Can they? Is there a way to track me etc? And is there a way to track if I've used any at all? When I call the data usage number, it tells me "information not available" since I don't have the data plan…

But yah.

No they can't

No, they won't charge you since you are not using their network when on Wi-Fi and not sending/ receiving data across GSM or 3G
as to whether they can track you- yes "they" can. Your phone has an IMEI unique to the phone, a UDID number again unique and the router will have a mac board with a unique number and then there's the IP address. Any one of these numbers is uniquely traceable and can be used singly or in conjunction with others to locate you or "sniff" your traffic.also, what are you using to access? Is it a t-mobile browser or standalone like bolt?
i hasten to add that although all things are possible with effort, your phone company wouldn't (or shouldn't) be able to track you in real time across networks not belonging to them- they could possibly see data residing on a network connected phone and this data could and does record past usage. Your phone collects all sorts of data that could be used to gather intelligence on its user but why would a phone company bother when there's so much collected digitally anyway?
if you are asking what "the man" can see then the answer is yes "they" can see everything if they decide they want to