Can AT&T tell if i've ever jailbroken my iPhone?

I've been thinking about jailbreaking my iPhone 4 lately, but I have some concerns regarding exactly how to do it and what it does, but most importantly if AT&T can tell. I read that restoring/resetting your phone will get rid of jailbreak, but I also heard that, even if you reset it, AT&T can still tell you did it at one time. Does anyone know if this is true? Also, if anyone has any tips on jailbreaking, i'd greatly appreciate it!

They can't tell - and if they could it would be VERY illegal for them so they would never admit it.

No they can't tell. Jailbreaks available here:
www.howtoidevice.com

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