Its like ISP's You could be going to a web page that sells illicit chemicals in China, but the only info they will keep unless police have suspicion first, as that your computer sent information to that computer at this time and date, and what port and transfer protocol it used, same with what Sustanon says, except messages are saved in Australia by law, but even longer, for billing purposes the time and date of all calls and SMS are saved for around 7 years, just not the content. Think of all those MMS's being sent around, they don't want to hold onto them for too long it creates extra work load on servers or makes them god forbid employ another person or maintain older hardware.