Contact the previous owner, and ask him to give you his username and pw. If he doesn't want to, or doesn't remember or what have you, then your second option is to contact verizon. This could get tricky because your are not a VZW customer. Was the bb used on verizon or At&t before you bought it.
go back to his house where you picked up the phone ask him for the user name and password. It will be much harder for him to say no when you are at his front door.
wow...sounds like a complicated problem to fix since you have to go trough the old user again.....i bought mine off of craigslist as well luckily it was brand spanking new
I bought a Storm with the same problem. I activated with it with VZW, then found out the PIN was locked. Since I was the "owner" in VZW's eyes, they released the PIN with a simple call from me. Where does that leave you as an ATT customer? Maybe you could get a friend to activate the Storm on his account (replacing an existing line temporarily). He calls VZW to release the PIN, it is now assigned to his account. He reactivates his phone back on the account, freeing up the Storm for you. You now have the "previous owner" (your friend) able to release the PIN to you. Hassle? Yes. But in less than an hour, you may have your problem resolved. Give him $20 bucks for his trouble. **Naturally, no guarantee this will work.**
I did the same thing with Alltel. Just call Verizon and Let them know you bought the phone used online and that you were told by a friend that works at a Verizon Store that you need to call and check that the PIN is released. They should tell you the MEID Hex is free and released and then they will transfer you to a BB tech who will release your PIN. I told them I am waiting for my current contract to run out and that I am switching to Verizon and found a deal to good to pass up on the phone. They took care of this in no time and I am happily squared away with my Storm on Alltel now.