I think this was on the news recently. Some mayor in the US got caught sending texts to a lady. And it came out in the news that the cell companies keep texts for a week or two, or a month for the purpose of being able to send the text at a later time in case the receiving phone is off.
Most companies do keep a reconrd of text messages sent/recieved from your account.
THey will only access them in the case of a legal request to do so. Much like landline providers keep records of the incoming/outgoing local calls.
It's getting the legal documents needed to access them that's the stumbling block for most people.
I looked at my Bell cellular bill and it lists all of the text messages I have sent or received.
My bill does not show who they went to or came from, but it would make sense that Bell would have that info stored somewhere for X amount of time.
In the current missing persons case here in Ottawa, it was reported in the news that a bunch of text messages were exchanged between the missing person and the other party. The content of the discussion was noted by the father of the missing student, so the contents are kept in Rogers case. The missing person has a Rogers cell.
my girlfriends uncle was murdered before i even knew her... she said that when the famiily had to attend court to sue/charge the murderrer, they had a print out of the last text messages sent to and from the victums phone before the time he died, they were reading them aloud in the courtroom