The issue is that, unlike landlines, cell phones don't have public directories you can simply search when you want. The federal government haven't created directories for cell phones for two reasons, the first being that the owner details change too much. As people get new mobile phone numbers every few years, it is almost impossible for the federal government to keep their records up to date.
The second reason is as cell phones aren't tied to a central deal it would also be unfeasible to create a directory to check where they are primarily based or kept, making it a pointless venture, as no addresses could be listed.
These reasons have been the main obstacles to finding out who owns a particular mobile phone. However, the internet has changed this. There are companies such as Intelius and Reverse Phone Detective who are capable of providing accurate owner information for any cell phone in the United States.
These companies are widely known as reverse cellular phone lookup services. These websites offer a service that enables you to discover accurate information such as names and addresses from just a cell phone number. The businesses behind them purchase hundreds of thousands of public records from the likes of the government and advertising agencies. This data comprises cell phone numbers, names and addresses. They then put these records into a central database which you can, for a fee, search via their website.