Cartoon by Bob Englehart, Hartford Courant (Source)
Telecom providers are obliged to store the delivery data of who is calling/texting/mailing who, but it's very simple to manipulate the address of the sender. There are various commercial services available - for example Spoofcard - that enables calls or text messages from a fake number. This information also ends up in the provider's data storage. Because of the regulation to store this meta data, the false information is also ending up with the intelligence and law enforcement agencies.