gsmps,
You've obviously made some assumptions so I'll let you ride with it.
If I am wrong then please indulge me with old fashioned transparency and englightenment:
If it were so easy to get unlock codes from wireless carriers without restrictions then why are there so may flourishing websites offering to unlock your phone/Blackberry for a price? (yours included)
By your statement, one could deduce that they could simply purchase a phone or Blackberry from any wireless carrier for the lowest price and then immediately call them to get the unlock code for free.
So again, if there are no restrictions, terms, conditions, or hoops to jump through, then why would someone pay to get the unlock code instead of getting it from their wireless carrier for free?
Inphektion,
At no time did I say that unlocking your Blackberry voids your warranty, causes damage, or prevents you from getting it repaired or replaced.
What I am saying and will say again is that certain carriers, VZW being one, have expressly stated in their Terms and Conditions that you are not allowed to unlock your 8830 for use on another carrier's GSM network.
Some carriers, T-Mobile for example, will give you the unlock code with little fuss. Other carriers make you meet certain terms and conditions before they will give it to you.
I am well aware of the fact that you can lock and unlock Blackberry devices and doing so does not damage them. For the record, I have unlocked several Blackberrys for use overseas. I used the unlock codes given to me by the wireless carriers we have contracts with. They gave me the unlock codes for free. Certain wireless carriers required us to meet their terms and conditions before they would give them to us. Your mileage may vary.
I will restate my answer to the OP's question:
does unlocking a Blackberry void the Carrier's warranty ?
No, it does not void the warranty.
Unlocking your phone from a third party without meeting certain wireless carrier's requirements, violates that carrier's terms and conditions.
If you meet their requirements, they will give you the unlock code for free.