masterx: If you buy an imei-blocked phone, then it's stolen (as you're basically saying yourself). Why on earth would you then think it's ok to _use_ the phone, by spoofing the imei? It's exactly things like that which creates a market for those gangs from certain parts of Europe which are currently doing the burglar rounds in my own and other countries. Without a market this extremely annoying thieveries wouldn't be an issue.
Well i think there is more reasons to change IMEI than using stolen phone. I think this is only one way to be anonymous and use gsm phone.
It has nothing with anonymity - the phone IMEI is known for mobile providers and SIM card issuer only. In most countries they don't give it anybody besides police. Mots likely - cheating one or both of it (phone providers or police).