By asking users for almost no identifiable information, Merrill wants to protect them from one of the most intractable privacy problems in modern technology: Despite whatever surveillance-resistant communications apps you might use, phone carriers will always know which of their customers’ phones are connecting to which cell towers and when. Carriers have frequently handed that information over to data brokers willing to pay for it—or any FBI or ICE agent that demands it with a court order

This is pretty pointless i believe. Your sim location can always be triangulated which means you will immediately identified if you ever go home with the sim card active.

All the feds have to do is either know where you live, or any specific location they know you were at, or your phone number and they will instantly have the same degree of insight as they would have had if you signed up to the provider with your name.