i have a friend that just bought a 8700c and he tried setting up a blackberry email up and it said that the PIN was already in use. and we read something about releasing the PIN and IMEI numbers?
i dont know what that means or how to do it, so if anyone knows any information about this please respond.

Read the FAQ "Buying a used BB on eBay" Buying a BlackBerry off eBay - BlackBerryFAQ

The seller has to call their carrier and cancel their BIS account. Then you call your carrier, set up a BB data plan, activate the BB and set up your email.