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So that's one "yes, absolutely" and one "no, no way".
Should he really have googled for 2 hours to find out that the answer is "maybe"? I think this post is entirely justified.
 
Yes, you can "brick" your iPhone. That happens if you update the modem. It can also occur in other various ways. Please get the facts straight.

Isn't that only if he unlocks the phone via a software unlock, and then once he updates the baseband it'll render the phone useless. Jailbreaking doesn't touch the baseband.
 
in the iphone hacks forum, at least one person asks this exact question every. single. day.
yes, definitely search first

and no, you can't brick the phone jailbreaking
 
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