brand new yet bad esn...how?

[thekafka]

i was surfing ebay, trying to buy a htc touch pro. and i came a across one that the selller said that the Touch Pro was brand new sealed in box, yet the esn was bad for sprint and it could only be used for metro pcs...how is that. Wouldn't the serial number have to be activated at one point to become bad for whatever reason...and thus shouldnt the phone have been activated and programmed/taken out of it's box.....if anyone could explain how a situation like this could happen i would appreciate it. -thekafka