My issue with it is this,
"Friends" will say things over text that they would never say to your face. Being a middle school girl not that long ago, I remember getting on MSN chat during sleepovers and girls saying terrible things to each other. Girls would log on and ask you what you thought about something or someone while the other person was there. Once a girl pretended to be a guy I liked and asked me out. Recently my friends middle school sister was at a birthday party, she gave her friends her brothers number and they started texting him anonymously from a friends phone. It used to be call a number and hang up, it has evolved into anonymous texting ( texting a person from a phone number they don't know).
Personally, I feel for a 12 yr old its an unnecessary form of communication, that places added stress on children at a difficult time when they are most vulnerable.
This is called cyber bulling. This can happen even if your child does not have a cell phone or Facebook or very strict internet action.
ADL has a lot of information on cyberbulling -- http://www.adl.org/cyberbullying/ because your child does not have access to technology it doesn't mean they can't/won't be cyberbullied.
They can call your home phone, ask for her and then call her bad names just as easy on the cell. I forgot the kid's name I read about but there was a web site that had his name and said "I hate" everyone at school knew about it. It was up for months before it was taken down. Denying your kids cell phones and net access to prevent it -- really is putting your head in the sand about cyberbulling and how to handle it. I would encourage all parents to look into the adl information and many other websites out there about bulling and cyberbulling.
My 12 year old has a cell phone like many people in her class. They get them taken away if they are caught texting without permission. She knows to turn if off in movies and dinner time. Or she looses the phone. Her friends know we are mean about it. If it gets taken away at school we are suppose to come up and get it. But she knows if it gets taken away at school she will get a new phone when she can afford to buy one.
My son is 16 and a sophmore. He knows the rules.
They both have learned to ignore text and the phone. We ignore our home and cell phones when we eating or driving. They know if they call while we are driving it will be ignored.