Bought a 3GS i want to use it buy iam afraid ATT will add data plan Need some advice

[Mujahidmd]

I bought a 3Gs from the the att store by adding a line on my family plan for my father. Today i called them and told att them that there wasnt a iPhone on that line anymore and to remove the data plan. I gave them the IMEI # of my samsung and they removed the data plan from the new line. This is where i need your guys advice i want to use the 3GS on my line (not my fathers) i currently have data blocked on my line except for text messages. I had a 3G before (got off craigslist then it got stolen) and i had jailbroken the phone and used that phone for about 5 months and ATT never added the data plan or charged me any other fees. I want to do the same for the 3GS but i have one question:
1) The phone isnt jailbroken (its running 3.01) so when i put my sim card into it will att add the data plan back on to my line?

(Those who are wondering why i dont want the data plan because almost everywhere i go i have wifi)

[Cer0]

Sometimes they do "sweeps" of phones and can see you are running an iPhone IMEI. Some people have gotten away with the talking getting a data block but ATT contracts have tricky words about the iPhone and Data plans.

[Mujahidmd]

yeah thats what i heard when i used my 3G that sometimes they do sweeps but they never added a data plan on my line and i had data blocked on it too. I guess ill try it and see what happens

Sometimes they do "sweeps" of phones and can see you are running an iPhone IMEI. Some people have gotten away with the talking getting a data block but ATT contracts have tricky words about the iPhone and Data plans.