Back in June, I upgraded from my data-less blackberry 8100 to an LG xenon (AT&T) so I could afford data since it is only $10 on the family plan for a non-smartphone. Recently I found my old blackberry. I took my SIM out of the Xenon and placed it in my Blackberry and have been using MEdia net. My sister, owner of the plan, received a text reading "Your SmarthPhone has been activated!" Is this just because I put the SIM card in and started the phone? Also, since I have been using MEdia Net on the blackberry with a regular data plan, what's going to happen? Is AT&T going to start charging me $30 after they notice I'm "cheating?" If so, is there any way I can get around this? Very new at blackberries. Thank you for help ahead of time.

Or worse, they will charge you a per/MB fee, I don't know what it is.

It may take 6-10 weeks to show on a bill... but watch for it. Data ain't free.

But I have a Data Unlimited Plan. (granted, it's not Blackberry) And I am only using MEdia Net, no official Blackberry services. Is there a workaround I can do? Because I really love the exclusivity of apps for Blackberry, and there's basically nothing for the Xenon.

But you don't have THE BlackBerry Data Plan.

You know what, this conversation takes place on this forum over a dozen times a day. I don't think you'll get any special dispensation on the issue.

Read this:
What do I need a Data Plan for? - BlackBerryFAQ
And this:
How to use BlackBerry on Generic Data Plan - BlackBerryFAQ

And use this:
BlackBerryForums.com : Your Number One BlackBerry Community - Search Forums

Thank you. I'm going to switch right back to my LG Xenon. Excuse my nuisance.

ATT has been saying for some time now that they routinely sweep devices and will match IMEI to the proper data plan. Perhaps that was what was done in this case?

No nuisance at all, wouldn't have responded had it been.

I hope it didn't, although it most likely may have. Even if it did, I can have it changed and get my credit back because I only used the blackberry for an hour, just a few KBs.