Local usage details (LUDs) are logs of ingoing and outgoing calls associated with a specific phone number. Phone companies use this information to generate bills for their customers, and law enforcement agencies may request access to the data as part of an investigation if they think it will be relevant to their work. A court order is necessary to view LUDs, but the standards are less stringent than for warrants to search personal property like homes.
The raw LUDs provide basic information, and the phone company will apply appropriate rates and other details later. Usually, a simplified version of the list is reproduced on the customer's bill, providing information about outgoing toll calls so people can understand the charges. The bill does not include a list of incoming calls unless a customer accepted collect charges on an incoming call. Outgoing calls within a local call area, where no toll applies, may not be listed.
Law enforcement agencies that want to access LUDs will need to approach a judge and explain why the data is necessary or helpful. They can access both landline and cell phone call data as part of an investigation. The phone company must turn over the material, and in some cases, customers may not be notified about the inspection of the phone records, depending on regional laws. Phone data may be useful for tracking transactions, identifying contacts, and other aspects of an investigation.
Phone companies keep LUDs for varying lengths of time. The company usually has an internal policy to keep logs long enough to be able to address customer disputes by turning to the raw data, and the law may require companies to keep this information for a set length of time as well. Some companies move data to an offsite storage facility, archiving it rather than destroying it in case they need it in the future.
Customers with concerns about potential uses of their LUDs can ask the phone company about its privacy policies and get information on regional laws in their area. If the data becomes subject to a court order, sometimes the phone company must notify customers to make them aware, while in other cases this does not occur. Usually, privacy protections are more strict for landlines than cell phones. Privacy laws are often in a state of flux, and it is important to check the most recent information to get an accurate picture of how and when private data is available to law enforcement officers.